2021 Top Malware Strains | CISA


Agent Tesla

alert any any -> any any (msg:”HTTP GET request /aw/aw.exe”; flow:established,to_server; sid:1; rev:1; content:”GET”; http_method; content:”/aw/aw.exe”; http_uri; reference:url, https://www.datto.com/blog/what-is-agent-tesla-spyware-and-how-does-it-work; metadata:service http;)

AZORult

alert tcp any any -> any any (msg:”HTTP Server Content Data contains ‘llehS|2e|tpircSW'”; sid:1; rev:1; flow:established,from_server; file_data; content:”llehS|2e|tpircSW”; nocase; fast_pattern:only; pcre:”/GCM(?:\x20|%20)\*W-O\*/i”; reference:url,maxkersten.nl/binary-analysis-course/malware-analysis/azorult-loader-stages/; metadata:service http;)

AZORult

alert tcp any any -> any any (msg:”HTTP POST Client Body contains ‘J/|fb|’ and “https://us-cert.cisa.gov/”fb|'”; sid:1; rev:1; flow:established,to_server; content:”POST”; http_method; content:”.php”; http_uri; content:”J/|fb|”; http_client_body; fast_pattern; content:”https://us-cert.cisa.gov/”fb|”; http_client_body; depth:11; content:!”Referer|3a 20|”; http_header; metadata:service http;)

FormBook

alert tcp any any -> any any (msg:”HTTP URI POST contains ‘&sql=1’ at the end”; sid:1; rev:1; flow:established,to_server; content:”&sql=1″; http_uri; fast_pattern:only; content:”POST”; http_method; pcre:”/(?(DEFINE)(?’b64std'[a-zA-Z0-9+\/=]+?))(?(DEFINE)(?’b64url'[a-zA-Z0-9_-]+?))^\/[a-z0-9]{3,4}\/\?(?P>b64url){3,8}=(?P>b64std){40,90}&(?P>b64url){2,6}=(?P>b64url){4,11}&sql=1$/iU”; reference:url,www.malware-traffic-analysis.net/2018/02/16/index.html; metadata:service http;)

alert tcp any any -> any any (msg:”HTTP URI GET/POST contains ‘/list/hx28/config.php?id='”; sid:1; rev:1; flow:established,to_server; content:”/list/hx28/config.php?id=”; http_uri; fast_pattern:only; content:”Connection|3a 20|close|0d 0a|”; http_header; reference:url,www.fireeye.com/blog/threat-research/2017/10/formbook-malware-distribution-campaigns.html; metadata:service http;)

Ursnif

alert tcp any any -> any any (msg:”HTTP POST Data contains .bin filename, long URI contains ‘/images/'”; sid:1; rev:1; flow:established,to_server;  urilen:>60,norm; content:”/images/”; http_uri; depth:8; content:”POST”; nocase; http_method; content:”Content-Disposition|3a 20|form-data|3b 20|name=|22|upload_file|22 3b 20|filename=|22|”; http_client_body; content:”|2e|bin|22 0d 0a|”; http_client_body; distance:1; within:32; fast_pattern;  reference:url,www.broadanalysis.com/2016/03/23/angler-ek-sends-data-stealing-payload/; metadata:service http;)

alert tcp any any -> any any (msg:”HTTP URI GET/POST contains ‘/images/’ plus random sub directories and an Image File (Ursnif)”; sid:1; rev:1; flow:established,to_server;  content:”/images/”; http_uri; fast_pattern:only; content:!”Host: www.urlquery.net”; http_header; pcre:”/\/images(\/(?=[a-z0-9\_]{0,22}[A-Z][a-z0-9\_]{0,22}[A-Z])(?=[A-Z0-9\_]{0,22}[a-z])[A-Za-z0-9\_]{1,24}){5,20}\/[a-zA-Z0-9\_]+\.(?:gif|jpeg|jpg|bmp)$/U”; metadata:service http)

LokiBot

alert tcp any any -> any any (msg:”HTTP Client Header contains ‘User-Agent|3a 20|Mozilla/4.08 (Charon|3b| Inferno)'”; sid:1; rev:1; flow:established,to_server; content:”User-Agent|3a 20|Mozilla/4.08 (Charon|3b| Inferno)|0d 0a|”; http_header; fast_pattern:only; metadata:service http; )

LokiBot

alert tcp any any -> any any (msg:”HTTP URI POST contains ‘/*/fre.php’ post-infection”; sid:1; rev:1; flow:established,to_server; content:”/fre.php”; http_uri; fast_pattern:only; urilen:<50,norm; content:”POST”; nocase; http_method; pcre:”/\/(?:alien|loky\d|donep|jemp|lokey|new2|loki|Charles|sev7n|dbwork|scroll\/NW|wrk|job|five\d?|donemy|animation\dkc|love|Masky|v\d|lifetn|Ben)\/fre\.php$/iU”; metadata:service http;)

LokiBot

alert tcp any any -> any any (msg:”HTTP URI POST contains ‘/w.php/'”; sid:1; rev:1; flow:established,to_server; content:”/w.php/”; http_uri; fast_pattern:only; content:”POST”; nocase; http_method; pcre:”/\/\w+\/w\.php\/[a-z]{13}$/iU”;  metadata:service http;)

MOUSEISLAND

alert tcp any any -> any any (msg:”HTTP URI GET contains ‘/assets/<8-80 hex>/<4-16 alnum>?<3-6 alnum>='”; sid:9206287; rev:1; flow:established,to_server; content:”/assets/”; http_uri; fast_pattern:only; content:”HTTP/1.1|0d 0a|”; depth:256; content:!”|0d 0a|Cookie:”; content:!”|0d 0a|Referer:”; pcre:”/\/assets\/[a-fA-F0-9/]{8,80}\/[a-zA-Z0-9]{4,16}\?[a-z0-9]{3,6}=/U”;  metadata:service http;)

NanoCore

alert tcp any any -> any 25 (msg:”SMTP Attachment Filename ‘Packinglist-Invoice101.pps'”; sid:1; rev:1; flow:established,to_server,only_stream; content:”Content-Disposition|3a 20|attachment|3b|”; content:”Packinglist-Invoice101.pps”; nocase; distance:0; fast_pattern; pcre:”/Content-Disposition\x3a\x20attachment\x3b[\x20\t\r\n]+?(?:file)*?name=\x22*?Packinglist-Invoice101\.pps\x22*?/im”; reference:cve,2014-4114; reference:msb,MS14-060; reference:url,researchcenter.paloaltonetworks.com/2015/06/keybase-keylogger-malware-family-exposed/; reference:url,www.fidelissecurity.com/sites/default/files/FTA_1017_Phishing_in_Plain_Sight-Body-FINAL.pdf; reference:url,www.fidelissecurity.com/sites/default/files/FTA_1017_Phishing_in_Plain_Sight-Appendix-FINAL.pdf;)

NanoCore

alert tcp any any -> any any (msg:”HTTP Client Header contains ‘Host|3a 20|frankief hopto me’ (GenericKD/Kazy/NanoCore/Recam)”; sid:1; rev:1; flow:established,to_server; content:”Host|3a 20|frankief|2e|hopto|2e|me|0d 0a|”; http_header; fast_pattern:only;  metadata:service http;)

NanoCore

alert tcp any any -> any any (msg:”HTTP GET URI contains ‘FAD00979338′”; sid:1; rev:1; flow:established,to_server; content:”GET”; http_method; content:”getPluginName.php?PluginID=FAD00979338″; fast_pattern; http_uri; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg:”HTTP URI GET /t?v=2&c= (Qakbot)”; sid:1; rev:1; flow:established,to_server; content:”/t?v=2&c=”; http_uri; depth:9; fast_pattern; reference:url,www.symantec.com/content/en/us/enterprise/media/security_response/whitepapers/w32_qakbot_in_detail.pdf;)

Qakbot

alert tcp any any -> any 21 (msg:”Possible FTP data exfiltration”; sid:1; rev:1; flow:to_server,established; content:”STOR si_”; content:”.cb”; within:50; reference:url,attack.mitre.org/techniques/T1020; reference:url,www.virustotal.com/en/file/3104ff71bf880bc40d096eca7d1ccc3f762ea6cc89743c6fef744fd76d441d1b/analysis/; metadata:service ftp-ctrlchan;)

Qakbot

alert tcp any any -> any any (msg:”Malicious executable download attempt”; sid:1; rev:1; flow:to_client,established; file_type:MSEXE; file_data; content:”|52 DB 91 CB FE 67 30 9A 8E 72 28 4F 1C A9 81 A1 AA BE AC 8D D9 AB E4 15 EF EA C6 73 89 9F CF 2E|”; fast_pattern:only; reference:url,virustotal.com/#/file/ad815edc045c779628db3a3397c559ca08f012216dfac4873f11044b2aa1537b/detection; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg:”HTTP POST URI contains ‘odin/si.php?get&'”; sid:1; rev:1; flow:to_server,established; content:”/odin/si.php?get&”; fast_pattern:only; http_uri; content:”news_slist”; http_uri; content:”comp=”; http_uri;  reference:url,www.virustotal.com/en/file/478132b5c80bd41b8c11e5ed591fdf05d52e316d40f7c4abf4bfd25db2463dff/analysis/1464186685/; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg:”HTTP URI contains ‘/random750x750.jpg?x='”; sid:1; rev:1; flow:to_server,established; content:”/random750x750.jpg?x=”; fast_pattern:only; http_uri; content:”&y=”; http_uri; content:”Accept|3a 20|application/x-shockwave-flash, image/gif, image/jpeg, image/pjpeg, */*|0d 0a|”; http_header; content:”Cache-Control|3a 20|no-cache|0d 0a|”; http_header; content:!”Accept-“; http_header; content:!”Referer”; http_header;  reference:url,www.virustotal.com/en/file/1826dba769dad9898acd95d6bd026a0b55d0a093a267b481695494f3ab547088/analysis/1461598351/; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg:”HTTP URI contains ‘/datacollectionservice.php3′”; sid:1; rev:1; flow:to_server,established; content:”/datacollectionservice.php3″; fast_pattern:only; http_uri; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg:”HTTP header contains ‘Accept|3a 20|application/x-shockwave-flash, image/gif, image/jpeg, image/pjpeg, */*|0d 0a|'”; sid:1; rev:1; flow:to_server,established; urilen:30<>35,norm; content:”btst=”; http_header; content:”snkz=”; http_header; content:”Accept|3a 20|application/x-shockwave-flash, image/gif, image/jpeg, image/pjpeg, */*|0d 0a|”; fast_pattern:only; http_header; content:”Cache-Control|3a 20|no-cache|0d 0a|”; http_header; content:!”Connection”; http_header; content:!”Referer”; http_header;  reference:url,www.virustotal.com/en/file/1826dba769dad9898acd95d6bd026a0b55d0a093a267b481695494f3ab547088/analysis/1461598351/; metadata:service http;)

Qakbot

alert tcp any any -> any 21 (msg:”Possible ps_dump FTP exfil”; sid:1; rev:1; flow:to_server,established; content:”ps_dump”; fast_pattern:only; pcre:”/ps_dump_[^_]+_[a-z]{5}\d{4}\x2Ekcb/smi”;  reference:url,www.threatexpert.com/report.aspx?md5=8171d3223f89a495f98c4e3a65537b8f; metadata:service ftp;)

Qakbot

alert tcp any any -> any 21 (msg:”Possible seclog FTP exfil”; sid:1; rev:1; flow:to_server,established; content:”seclog”; fast_pattern:only; pcre:”/seclog_[a-z]{5}\d{4}_\d{10}\x2Ekcb/smi”;  reference:url,www.threatexpert.com/report.aspx?md5=8171d3223f89a495f98c4e3a65537b8f; metadata:service ftp;)

Qakbot

alert tcp any any -> any any (msg:”HTTP URI contains ‘/cgi-bin/jl/jloader.pl'”; sid:1; rev:1; flow:to_server,established; content:”/cgi-bin/jl/jloader.pl”; fast_pattern:only; http_uri;  reference:url,www.threatexpert.com/report.aspx?md5=8171d3223f89a495f98c4e3a65537b8f; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg:”HTTP URI contains ‘/cgi-bin/clientinfo3.pl'”; sid:1; rev:1; flow:to_server,established; content:”/cgi-bin/clientinfo3.pl”; fast_pattern:only; http_uri;  reference:url,www.threatexpert.com/report.aspx?md5=8171d3223f89a495f98c4e3a65537b8f; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg:”HTTP URI contains ‘/u/updates.cb'”; sid:1; rev:1; flow:to_server,established; content:”/u/updates.cb”; fast_pattern:only; http_uri; pcre:”/^Host\x3A[^\r\n]+((up\d+)|(adserv))/Hmi”; reference:url,www.threatexpert.com/report.aspx?md5=8171d3223f89a495f98c4e3a65537b8f; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg:”HTTP response content contains ‘|47 65 74 46 69 6C 65 46 72 6F 6D 52 65 73 6F 75 72 63 65 73 28 29 3A 20 4C 6F 61 64 52 65 73 6F 75 72 63 65 28 29 20 66 61 69 6C 65 64|'”; sid:1; rev:1; flow:to_client,established; file_data; content:”|47 65 74 46 69 6C 65 46 72 6F 6D 52 65 73 6F 75 72 63 65 73 28 29 3A 20 4C 6F 61 64 52 65 73 6F 75 72 63 65 28 29 20 66 61 69 6C 65 64|”; fast_pattern:only; content:”|47 65 74 46 69 6C 65 46 72 6F 6D 52 65 73 6F 75 72 63 65 73 28 29 3A 20 43 72 65 61 74 65 46 69 6C 65 28 29 20 66 61 69 6C 65 64|”; content:”|52 75 6E 45 78 65 46 72 6F 6D 52 65 73 28 29 20 73 74 61 72 74 65 64|”; content:”|73 7A 46 69 6C 65 50 61 74 68 3D|”; content:”|5C 25 75 2E 65 78 65|”; reference:url,www.virustotal.com/en/file/23e72e8b5e7856e811a326d1841bd2ac27ac02fa909d0a951b0b8c9d1d6aa61c/analysis; metadata:service ftp-data,service http;)

Qakbot

alert tcp any any -> any any (msg:”HTTP POST URI contains ‘v=3&c=””; sid:1; rev:1; flow:to_server,established; content:”/t”; http_uri; content:”POST”; http_method; content:”v=3&c=”; depth:6; http_client_body; content:”==”; within:2; distance:66; http_client_body;  reference:url,www.virustotal.com/en/file/3104ff71bf880bc40d096eca7d1ccc3f762ea6cc89743c6fef744fd76d441d1b/analysis/; metadata:service http;)

Qakbot

alert tcp any any -> any any (msg:”HTTP URI GET contains “/<alpha>/595265.jpg'”; sid:1; rev:1; flow:established,to_server; content:”/595265.jpg”; http_uri; fast_pattern:only; content:”GET”; nocase; http_method; pcre:”/^\/[a-z]{5,15}\/595265\.jpg$/U”;  reference:url,www.virustotal.com/gui/file/3104ff71bf880bc40d096eca7d1ccc3f762ea6cc89743c6fef744fd76d441d1b/detection; metadata:service http;)

Remcos

alert tcp any any -> any any (msg:”Non-Std TCP Client Traffic contains ‘|1b 84 d5 b0 5d f4 c4 93 c5 30 c2|’ (Checkin #23)”; sid:1; rev:1; flow:established,to_server; dsize:<700; content:”|1b 84 d5 b0 5d f4 c4 93 c5 30 c2|”; depth:11; fast_pattern; content:”|da b1|”; distance:2; within:2;  reference:url,blog.trendmicro.com/trendlabs-security-intelligence/analysis-new-remcos-rat-arrives-via-phishing-email/; reference:url,isc.sans.edu/forums/diary/Malspam+using+passwordprotected+Word+docs+to+push+Remcos+RAT/25292/; reference:url,www.malware-traffic-analysis.net/2019/09/03/index.html; reference:url,www.malware-traffic-analysis.net/2017/10/27/index.html;)

TrickBot

alert tcp any any -> any any (msg:”HTTP Client Header contains ‘host|3a 20|tpsci.com'”; sid:1; rev:1; flow:established,to_server; content:”host|3a 20|tpsci.com”; http_header; fast_pattern:only; metadata:service http;)

TrickBot

alert tcp any any -> any any (msg:”HTTP Client Header contains ‘User-Agent|3a 20|*Loader'”; sid:1; rev:1; flow:established,to_server; content:”User-Agent|3a 20|”; http_header; content:”Loader|0d 0a|”; nocase; http_header; distance:0; within:24; fast_pattern; metadata:service http;)

TrickBot

alert udp any any <> any 53 (msg:”DNS Query/Response onixcellent com (UDP)”; sid:1; rev:1; content:”|0B|onixcellent|03|com|00|”; fast_pattern:only; reference:url,medium.com/stage-2-security/anchor-dns-malware-family-goes-cross-platform-d807ba13ca30; priority:1; metadata:service dns;)

TrickBot

alert tcp any any -> any any (msg:”SSL/TLS Server X.509 Cert Field contains ‘C=XX, L=Default City, O=Default Company Ltd'”; sid:1; rev:2; flow:established,from_server; ssl_state:server_hello; content:”|31 0b 30 09 06 03 55 04 06 13 02|XX”; nocase; content:”|31 15 30 13 06 03 55 04 07 13 0c|Default City”; nocase; content:”|31 1c 30 1a 06 03 55 04 0a 13 13|Default Company Ltd”; nocase; content:!”|31 0c 30 0a 06 03 55 04 03|”;  reference:url,www.virustotal.com/gui/file/e9600404ecc42cf86d38deedef94068db39b7a0fd06b3b8fb2d8a3c7002b650e/detection; metadata:service ssl;)

TrickBot

alert tcp any any -> any any (msg:”SSL/TLS Server X.509 Cert Field contains ‘C=AU, ST=Some-State, O=Internet Widgits Pty Ltd'”; sid:1; rev:1; flow:established,from_server; ssl_state:server_hello; content:”|31 0b 30 09 06 03 55 04 06 13 02|AU”; content:”|31 13 30 11 06 03 55 04 08 13 0a|Some-State”; distance:0; content:”|31 21 30 1f 06 03 55 04 0a 13 18|Internet Widgits Pty Ltd”; distance:0; fast_pattern; content:”|06 03 55 1d 13 01 01 ff 04 05 30 03 01 01 ff|”;  reference:url,www.virustotal.com/gui/file/e9600404ecc42cf86d38deedef94068db39b7a0fd06b3b8fb2d8a3c7002b650e/detection; metadata:service ssl;)

TrickBot

alert tcp any any -> any any (msg:”HTTP Client Header contains ‘boundary=Arasfjasu7′”; sid:1; rev:1; flow:established,to_server; content:”boundary=Arasfjasu7|0d 0a|”; http_header; content:”name=|22|proclist|22|”; http_header; content:!”Referer”; content:!”Accept”; content:”POST”; http_method; metadata:service http;)

TrickBot

alert tcp any any -> any any (msg:”HTTP Client Header contains ‘User-Agent|3a 20|WinHTTP loader/1.'”; sid:1; rev:1; flow:established,to_server; content:”User-Agent|3a 20|WinHTTP loader/1.”; http_header; fast_pattern:only; content:”.png|20|HTTP/1.”; pcre:”/^Host\x3a\x20(?:\d{1,3}\.){3}\d{1,3}(?:\x3a\d{2,5})?$/mH”; content:!”Accept”; http_header; content:!”Referer|3a 20|”; http_header; metadata:service http;)

TrickBot

alert tcp any any -> any any (msg:”HTTP Server Header contains ‘Server|3a 20|Cowboy'”; sid:1; rev:1; flow:established,from_server; content:”200″; http_stat_code; content:”Server|3a 20|Cowboy|0d 0a|”; http_header; fast_pattern; content:”content-length|3a 20|3|0d 0a|”; http_header; file_data; content:”/1/”; depth:3; isdataat:!1,relative; metadata:service http;)

TrickBot

alert tcp any any -> any any (msg:”HTTP URI POST contains C2 Exfil”; sid:1; rev:1; flow:established,to_server; content:”Content-Type|3a 20|multipart/form-data|3b 20|boundary=——Boundary”; http_header; fast_pattern; content:”User-Agent|3a 20|”; http_header; distance:0; content:”Content-Length|3a 20|”; http_header; distance:0; content:”POST”; http_method; pcre:”/^\/[a-z]{3}\d{3}\/.+?\.[A-F0-9]{32}\/\d{1,3}\//U”; pcre:”/^Host\x3a\x20(?:\d{1,3}\.){3}\d{1,3}$/mH”; content:!”Referer|3a|”; http_header; metadata:service http;)

TrickBot

alert tcp any any -> any any (msg:”HTTP URI GET/POST contains ‘/56evcxv'”; sid:1; rev:1; flow:established,to_server; content:”/56evcxv”; http_uri; fast_pattern:only;  metadata:service http;)

TrickBot

alert icmp any any -> any any (msg:”ICMP traffic conatins ‘hanc'”; sid:1; rev:1; itype:8; icode:0; dsize:22; content:”hanc”; depth:4; fast_pattern; pcre:”/hanc[0-9a-f]{16}../i”;  reference:url,labs.sentinelone.com/anchor-project-for-trickbot-adds-icmp/;)

TrickBot

alert tcp any any -> any any (msg:”HTTP Client Header contains POST with ‘host|3a 20|*.onion.link’ and ‘data=””; sid:1; rev:1; flow:established,to_server; content:”POST”; nocase; http_method; content:”host|3a 20|”; http_header; content:”.onion.link”; nocase; http_header; distance:0; within:47; fast_pattern; file_data; content:”data=”; distance:0; within:5; metadata:service http;)

TrickBot

alert tcp any 80 -> any any (msg:”Non-Std TCP Client Traffic contains PowerView Script Download String”; sid:1; rev:1; flow:established,from_server; content:”PowerView.ps1″; content:”PSReflect/master/PSReflect.psm1″; fast_pattern:only; content:”function New-InMemoryModule”; metadata:service else-ports;)

TrickBot

alert tcp any any -> any 445 (msg:”Non-Std TCP Client SMB Traffic contains “44783m8uh77g818_nkubyhu5vfxxbh878xo6hlttkppzf28tsdu5kwppk_11c1jl'”; sid:1; rev:1; flow:established,to_server; content:”44783m8uh77g818_nkubyhu5vfxxbh878xo6hlttkppzf28tsdu5kwppk_11c1jl”; fast_pattern:only; metadata:service netbios-ssn,service and-ports;)

TrickBot

alert tcp any any -> any [80,443,8082] (msg:”Non-Std TCP Client Traffic contains ‘–aksgja8s8d8a8s97′”; sid:1; rev:1; flow:established,to_server; content:”–aksgja8s8d8a8s97″; fast_pattern:only; content:”name=|22|proclist|22|”;  metadata:service else-ports;)

TrickBot

alert tcp any any -> any any (msg:”HTTP Client Header contains ‘User-Agent|3a 20|WinHTTP loader/1.0′”; sid:1; rev:1; flow:established,to_server; content:”User-Agent|3a 20|WinHTTP loader/1.0|0d 0a|”; http_header; fast_pattern:only; pcre:”/\/t(?:oler|able)\.png/U”; metadata:service http;)

TrickBot

alert tcp any any -> any [443,8082] (msg:”Non-Std TCP Client Traffic contains ‘_W<digits>.'”; sid:1; rev:1; flow:established,to_server; content:”_W”; fast_pattern:only; pcre:”/_W\d{6,8}\./”; metadata:service else-ports;)

TrickBot

alert tcp any [443,447] -> any any (msg:”SSL/TLS Server X.509 Cert Field contains ‘example.com’ (Hex)”; sid:1; rev:1; flow:established,from_server; ssl_state:server_hello; content:”|0b|example.com”; fast_pattern:only; content:”Global Security”; content:”IT Department”; pcre:”/(?:\x09\x00\xc0\xb9\x3b\x93\x72\xa3\xf6\xd2|\x00\xe2\x08\xff\xfb\x7b\x53\x76\x3d)/”;  metadata:service ssl,service and-ports;)

TrickBot

alert tcp any any -> any any+F57 (msg:”HTTP URI GET contains ‘/anchor'”; sid:1; rev:1; flow:established,to_server; content:”/anchor”; http_uri; fast_pattern:only; content:”GET”; nocase; http_method; pcre:”/^\/anchor_?.{3}\/[\w_-]+\.[A-F0-9]+\/?$/U”; metadata:service http;)

TrickBot

alert udp any any <> any 53 (msg:”DNS Query/Response kostunivo com (UDP)”; sid:1; rev:1; content:”|09|kostunivo|03|com|00|”; fast_pattern:only;  reference:url,medium.com/stage-2-security/anchor-dns-malware-family-goes-cross-platform-d807ba13ca30;  metadata:service dns;)

TrickBot

alert udp any any <> any 53 (msg:”DNS Query/Response chishir com (UDP)”; sid:1; rev:1; content:”|07|chishir|03|com|00|”; fast_pattern:only; reference:url,medium.com/stage-2-security/anchor-dns-malware-family-goes-cross-platform-d807ba13ca30; metadata:service dns;)

TrickBot

alert udp any any <> any 53 (msg:”DNS Query/Response mangoclone com (UDP)”; sid:1; rev:1; content:”|0A|mangoclone|03|com|00|”; fast_pattern:only; reference:url,medium.com/stage-2-security/anchor-dns-malware-family-goes-cross-platform-d807ba13ca30; metadata:service dns;)

GootLoader

No signature available.

Source…

North Korean State-Sponsored Cyber Actors Use Maui Ransomware to Target the Healthcare and Public Health Sector


Summary

The Federal Bureau of Investigation (FBI), Cybersecurity and Infrastructure Security Agency (CISA), and the Department of the Treasury (Treasury) are releasing this joint Cybersecurity Advisory (CSA) to provide information on Maui ransomware, which has been used by North Korean state-sponsored cyber actors since at least May 2021 to target Healthcare and Public Health (HPH) Sector organizations.

This joint CSA provides information—including tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs)—on Maui ransomware obtained from FBI incident response activities and industry analysis of a Maui sample. The FBI, CISA, and Treasury urge HPH Sector organizations as well as other critical infrastructure organizations to apply the recommendations in the Mitigations section of this CSA to reduce the likelihood of compromise from ransomware operations. Victims of Maui ransomware should report the incident to their local FBI field office or CISA. 

The FBI, CISA, and Treasury highly discourage paying ransoms as doing so does not guarantee files and records will be recovered and may pose sanctions risks. Note: in September 2021, Treasury issued an updated advisory highlighting the sanctions risks associated with ransomware payments and the proactive steps companies can take to mitigate such risks. Specifically, the updated advisory encourages U.S. entities to adopt and improve cybersecurity practices and report ransomware attacks to, and fully cooperate with, law enforcement. The updated advisory states that when affected parties take these proactive steps, Treasury’s Office of Foreign Assets Control (OFAC) would be more likely to resolve apparent sanctions violations involving ransomware attacks with a non-public enforcement response.

For more information on state-sponsored North Korean malicious cyber activity, see CISA’s North Korea Cyber Threat Overview and Advisories webpage. 

Download the PDF version of this report: pdf, 553 kb.

Technical Details

Since May 2021, the FBI has observed and responded to multiple Maui ransomware incidents at HPH Sector organizations. North Korean state-sponsored cyber actors used Maui ransomware in these incidents to encrypt servers responsible for healthcare services—including electronic health records services, diagnostics services, imaging services, and intranet services. In some cases, these incidents disrupted the services provided by the targeted HPH Sector organizations for prolonged periods. The initial access vector(s) for these incidents is unknown.

Maui Ransomware

Maui ransomware (maui.exe) is an encryption binary. According to industry analysis of a sample of Maui (SHA256: 5b7ecf7e9d0715f1122baf4ce745c5fcd769dee48150616753fec4d6da16e99e) provided in Stairwell Threat Report: Maui Ransomware—the ransomware appears to be designed for manual execution [TA0002] by a remote actor. The remote actor uses command-line interface [T1059.008] to interact with the malware and to identify files to encrypt. 

Maui uses a combination of Advanced Encryption Standard (AES), RSA, and XOR encryption to encrypt [T1486] target files:

  1. Maui encrypts target files with AES 128-bit encryption. Each encrypted file has a unique AES key, and each file contains a custom header with the file’s original path, allowing Maui to identify previously encrypted files. The header also contains encrypted copies of the AES key.
  2. Maui encrypts each AES key with RSA encryption.
    • Maui loads the RSA public (maui.key) and private (maui.evd) keys in the same directory as itself. 
  3. Maui encodes the RSA public key (maui.key) using XOR encryption. The XOR key is generated from hard drive information (\\.\PhysicalDrive0).

During encryption, Maui creates a temporary file for each file it encrypts using GetTempFileNameW(). Maui uses the temporary to stage output from encryption. After encrypting files, Maui creates maui.log, which contains output from Maui execution. Actors likely exfiltrate [TA0010] maui.log and decrypt the file using associated decryption tools.

See Stairwell Threat Report: Maui Ransomware for additional information on Maui ransomware, including YARA rules and a key extractor.

Indicators of Compromise

See table 1 for Maui ransomware IOCs obtained from FBI incident response activities since May 2021. 
 

Table 1: Maui Ransomware IOCs

Indicator Type Value
Filename maui.exe
maui.log
maui.key
maui.evd
aui.exe
MD5 Hash 4118d9adce7350c3eedeb056a3335346
9b0e7c460a80f740d455a7521f0eada1
fda3a19afa85912f6dc8452675245d6b
2d02f5499d35a8dffb4c8bc0b7fec5c2
c50b839f2fc3ce5a385b9ae1c05def3a
a452a5f693036320b580d28ee55ae2a3
a6e1efd70a077be032f052bb75544358
802e7d6e80d7a60e17f9ffbd62fcbbeb
SHA256 Hash 5b7ecf7e9d0715f1122baf4ce745c5fcd769dee48150616753fec4d6da16e99e
45d8ac1ac692d6bb0fe776620371fca02b60cac8db23c4cc7ab5df262da42b78
56925a1f7d853d814f80e98a1c4890b0a6a84c83a8eded34c585c98b2df6ab19
830207029d83fd46a4a89cd623103ba2321b866428aa04360376e6a390063570
458d258005f39d72ce47c111a7d17e8c52fe5fc7dd98575771640d9009385456
99b0056b7cc2e305d4ccb0ac0a8a270d3fceb21ef6fc2eb13521a930cea8bd9f
3b9fe1713f638f85f20ea56fd09d20a96cd6d288732b04b073248b56cdaef878
87bdb1de1dd6b0b75879d8b8aef80b562ec4fad365d7abbc629bcfc1d386afa6

 

Attribution to North Korean State-Sponsored Cyber Actors

The FBI assesses North Korean state-sponsored cyber actors have deployed Maui ransomware against Healthcare and Public Health Sector organizations. The North Korean state-sponsored cyber actors likely assume healthcare organizations are willing to pay ransoms because these organizations provide services that are critical to human life and health. Because of this assumption, the FBI, CISA, and Treasury assess North Korean state-sponsored actors are likely to continue targeting HPH Sector organizations. 

Mitigations

The FBI, CISA, and Treasury urge HPH Sector organizations to:

  • Limit access to data by deploying public key infrastructure and digital certificates to authenticate connections with the network, Internet of Things (IoT) medical devices, and the electronic health record system, as well as to ensure data packages are not manipulated while in transit from man-in-the-middle attacks. 
  • Use standard user accounts on internal systems instead of administrative accounts, which allow for overarching administrative system privileges and do not ensure least privilege.  
  • Turn off network device management interfaces such as Telnet, SSH, Winbox, and HTTP for wide area networks (WANs) and secure with strong passwords and encryption when enabled. 
  • Secure personal identifiable information (PII)/patient health information (PHI) at collection points and encrypt the data at rest and in transit by using technologies such as Transport Layer Security (TPS). Only store personal patient data on internal systems that are protected by firewalls, and ensure extensive backups are available if data is ever compromised. 
  • Protect stored data by masking the permanent account number (PAN) when it is displayed and rendering it unreadable when it is stored—through cryptography, for example. 
  • Secure the collection, storage, and processing practices for PII and PHI, per regulations such as the Health Insurance Portability and Accountability Act of 1996 (HIPAA). Implementing HIPAA security measures can prevent the introduction of malware on the system. 
  • Implement and enforce multi-layer network segmentation with the most critical communications and data resting on the most secure and reliable layer. 
  • Use monitoring tools to observe whether IoT devices are behaving erratically due to a compromise. 
  • Create and regularly review internal policies that regulate the collection, storage, access, and monitoring of PII/PHI.

In addition, the FBI, CISA, and Treasury urge all organizations, including HPH Sector organizations, to apply the following recommendations to prepare for, mitigate/prevent, and respond to ransomware incidents.

Preparing for Ransomware

Mitigating and Preventing Ransomware

  • Install updates for operating systems, software, and firmware as soon as they are released. Timely patching is one of the most efficient and cost-effective steps an organization can take to minimize its exposure to cybersecurity threats. Regularly check for software updates and end-of-life notifications and prioritize patching known exploited vulnerabilities. Consider leveraging a centralized patch management system to automate and expedite the process.
  • If you use Remote Desktop Protocol (RDP), or other potentially risky services, secure and monitor them closely.
    • Limit access to resources over internal networks, especially by restricting RDP and using virtual desktop infrastructure. After assessing risks, if RDP is deemed operationally necessary, restrict the originating sources, and require multifactor authentication (MFA) to mitigate credential theft and reuse. If RDP must be available externally, use a virtual private network (VPN), virtual desktop infrastructure, or other means to authenticate and secure the connection before allowing RDP to connect to internal devices. Monitor remote access/RDP logs, enforce account lockouts after a specified number of attempts to block brute force campaigns, log RDP login attempts, and disable unused remote access/RDP ports.
    • Ensure devices are properly configured and that security features are enabled. Disable ports and protocols that are not being used for a business purpose (e.g., RDP Transmission Control Protocol Port 3389). 
    • Restrict Server Message Block (SMB) Protocol within the network to only access servers that are necessary and remove or disable outdated versions of SMB (i.e., SMB version 1). Threat actors use SMB to propagate malware across organizations.
    • Review the security posture of third-party vendors and those interconnected with your organization. Ensure all connections between third-party vendors and outside software or hardware are monitored and reviewed for suspicious activity.
    • Implement listing policies for applications and remote access that only allow systems to execute known and permitted programs under an established.
    • Open document readers in protected viewing modes to help prevent active content from running.
  • Implement user training program and phishing exercises to raise awareness among users about the risks of visiting suspicious websites, clicking on suspicious links, and opening suspicious attachments. Reinforce the appropriate user response to phishing and spearphishing emails. 
  • Require MFA for as many services as possible—particularly for webmail, VPNs, accounts that access critical systems, and privileged accounts that manage backups. 
  • Use strong passwords and avoid reusing passwords for multiple accounts. See CISA Tip Choosing and Protecting Passwords and National Institute of Standards and Technology (NIST) Special Publication 800-63B: Digital Identity Guidelines for more information.
  • Require administrator credentials to install software.
  • Audit user accounts with administrative or elevated privileges and configure access controls with least privilege in mind.
  • Install and regularly update antivirus and antimalware software on all hosts.
  • Only use secure networks and avoid using public Wi-Fi networks. Consider installing and using a VPN.
  • Consider adding an email banner to messages coming from outside your organizations.
  • Disable hyperlinks in received emails.

Responding to Ransomware Incidents

If a ransomware incident occurs at your organization:

  • Follow your organization’s Ransomware Response Checklist (see Preparing for Ransomware section). 
  • Scan backups. If possible, scan backup data with an antivirus program to check that it is free of malware. This should be performed using an isolated, trusted system to avoid exposing backups to potential compromise.
  • Follow the notification requirements as outlined in your cyber incident response plan. 
  • Report incidents to the FBI at a local FBI Field Office, CISA at us-cert.cisa.gov/report, or the U.S. Secret Service (USSS) at a USSS Field Office
  • Apply incident response best practices found in the joint Cybersecurity Advisory, Technical Approaches to Uncovering and Remediating Malicious Activity, developed by CISA and the cybersecurity authorities of Australia, Canada, New Zealand, and the United Kingdom.

Note: the FBI, CISA, and Treasury strongly discourage paying ransoms as doing so does not guarantee files and records will be recovered and may pose sanctions risks. 

Request for Information

The FBI is seeking any information that can be shared, to include boundary logs showing communication to and from foreign IP addresses, bitcoin wallet information, the decryptor file, and/or benign samples of encrypted files. As stated above, the FBI discourages paying ransoms. Payment does not guarantee files will be recovered and may embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. However, the FBI understands that when victims are faced with an inability to function, all options are evaluated to protect shareholders, employees, and customers. Regardless of whether you or your organization have decided to pay the ransom, the FBI, CISA, and Treasury urge you to promptly report ransomware incidents to the FBI at a local FBI Field Office, CISA at us-cert.cisa.gov/report, or the USSS at a USSS Field Office. Doing so provides the U.S. Government with critical information needed to prevent future attacks by identifying and tracking ransomware actors and holding them accountable under U.S. law.

Resources 

  • For more information and resources on protecting against and responding to ransomware, refer to StopRansomware.gov, a centralized, U.S. whole-of-government webpage providing ransomware resources and alerts.
  • CISA’s Ransomware Readiness Assessment is a no-cost self-assessment based on a tiered set of practices to help organizations better assess how well they are equipped to defend and recover from a ransomware incident.
  • A guide that helps organizations mitigate a ransomware attack and provides a Ransomware Response Checklists: CISA-Multi-State Information Sharing and Analysis Center (MS-ISAC) Joint Ransomware Guide.
  • The U.S. Department of State’s Rewards for Justice (RFJ) program offers a reward of up to $10 million for reports of foreign government malicious activity against U.S. critical infrastructure. See the RFJ website for more information and how to report information securely. 

Acknowledgements

The FBI, CISA, and Treasury would like to thank Stairwell for their contributions to this CSA. 

Contact Information

To report suspicious or criminal activity related to information found in this Joint Cybersecurity Advisory, contact your local FBI field office at fbi.gov/contact-us/field, or the FBI’s 24/7 Cyber Watch (CyWatch) at (855) 292-3937 or by e-mail at [email protected]. When available, please include the following information regarding the incident: date, time, and location of the incident; type of activity; number of people affected; type of equipment used for the activity; the name of the submitting company or organization; and a designated point of contact. To request incident response resources or technical assistance related to these threats, contact CISA at [email protected]

Revisions

July 6, 2022: Initial Version

Source…

#StopRansomware: MedusaLocker | CISA


Summary

Actions to take today to mitigate cyber threats from ransomware:
• Prioritize remediating
known exploited vulnerabilities.
• Train users to recognize and report phishing attempts.
• Enable and enforce multifactor authentication.

Note: this joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources.

The Federal Bureau of Investigation (FBI), the Cybersecurity and Infrastructure Security Agency (CISA), the Department of the Treasury, and the Financial Crimes Enforcement Network (FinCEN) are releasing this CSA to provide information on MedusaLocker ransomware. Observed as recently as May 2022, MedusaLocker actors predominantly rely on vulnerabilities in Remote Desktop Protocol (RDP) to access victims’ networks. The MedusaLocker actors encrypt the victim’s data and leave a ransom note with communication instructions in every folder containing an encrypted file. The note directs victims to provide ransomware payments to a specific Bitcoin wallet address. MedusaLocker appears to operate as a Ransomware-as-a-Service (RaaS) model based on the observed split of ransom payments. Typical RaaS models involve the ransomware developer and various affiliates that deploy the ransomware on victim systems. MedusaLocker ransomware payments appear to be consistently split between the affiliate, who receives 55 to 60 percent of the ransom; and the developer, who receives the remainder. 

Download the PDF version of this report: pdf, 633 kb

Technical Details

MedusaLocker ransomware actors most often gain access to victim devices through vulnerable Remote Desktop Protocol (RDP) configurations [T1133]. Actors also frequently use email phishing and spam email campaigns—directly attaching the ransomware to the email—as initial intrusion vectors [T1566].

MedusaLocker ransomware uses a batch file to execute PowerShell script invoke-ReflectivePEInjection [T1059.001]. This script propagates MedusaLocker throughout the network by editing the EnableLinkedConnections value within the infected machine’s registry, which then allows the infected machine to detect attached hosts and networks via Internet Control Message Protocol (ICMP) and to detect shared storage via Server Message Block (SMB) Protocol. 

MedusaLocker then: 

  • Restarts the LanmanWorkstation service, which allows registry edits to take effect. 
  • Kills the processes of well-known security, accounting, and forensic software. 
  • Restarts the machine in safe mode to avoid detection by security software [T1562.009].
  • Encrypts victim files with the AES-256 encryption algorithm; the resulting key is then encrypted with an RSA-2048 public key [T1486]. 
  • Runs every 60 seconds, encrypting all files except those critical to the functionality of the victim’s machine and those that have the designated encrypted file extension. 
  • Establishes persistence by copying an executable (svhost.exe or svhostt.exe) to the %APPDATA%\Roaming directory and scheduling a task to run the ransomware every 15 minutes. 
  • Attempts to prevent standard recovery techniques by deleting local backups, disabling startup recovery options, and deleting shadow copies [T1490].

MedusaLocker actors place a ransom note into every folder containing a file with the victim’s encrypted data. The note outlines how to communicate with the MedusaLocker actors, typically providing victims one or more email address at which the actors can be reached. The size of MedusaLocker ransom demands appears to vary depending on the victim’s financial status as perceived by the actors. 

Indicators of Compromise

Encrypted File Extensions
.1btc .matlock20 .marlock02 .readinstructions
.bec .mylock .jpz.nz .marlock11
.cn .NET1 .key1 .fileslocked
.datalock .NZ .lock .lockfilesUS
.deadfilesgr .tyco .lockdata7 .rs
.faratak .uslockhh .lockfiles .tyco
.fileslock .zoomzoom .perfection .uslockhh
.marlock13 n.exe .Readinstruction .marlock08
.marlock25 nt_lock20 .READINSTRUCTION  
.marlock6 .marlock01 .ReadInstructions  

 

Ransom Note File Names
how_to_ recover_data.html  how_to_recover_data.html.marlock01
instructions.html  READINSTRUCTION.html 
!!!HOW_TO_DECRYPT!!! How_to_recovery.txt
readinstructions.html  readme_to_recover_files
recovery_instructions.html  HOW_TO_RECOVER_DATA.html
recovery_instruction.html  

 

Payment Wallets
14oxnsSc1LZ5M2cPZeQ9rFnXqEvPCnZikc 
1DRxUFhvJjGUdojCzMWSLmwx7Qxn79XbJq 
18wRbb94CjyTGkUp32ZM7krCYCB9MXUq42 
1AbRxRfP6yHePpi7jmDZkS4Mfpm1ZiatH5
1Edcufenw1BB4ni9UadJpQh9LVx9JGtKpP
1DyMbw6R9PbJqfUSDcK5729xQ57yJrE8BC 
184ZcAoxkvimvVZaj8jZFujC7EwR3BKWvf 
14oH2h12LvQ7BYBufcrY5vfKoCq2hTPoev
bc1qy34v0zv6wu0cugea5xjlxagsfwgunwkzc0xcjj
bc1q9jg45a039tn83jk2vhdpranty2y8tnpnrk9k5q
bc1qz3lmcw4k58n79wpzm550r5pkzxc2h8rwmmu6xm
1AereQUh8yjNPs9Wzeg1Le47dsqC8NNaNM
1DeNHM2eTqHp5AszTsUiS4WDHWkGc5UxHf
1HEDP3c3zPwiqUaYuWZ8gBFdAQQSa6sMGw
1HdgQM9bjX7u7vWJnfErY4MWGBQJi5mVWV
1nycdn9ebxht4tpspu4ehpjz9ghxlzipll
12xd6KrWVtgHEJHKPEfXwMVWuFK4k1FCUF
1HZHhdJ6VdwBLCFhdu7kDVZN9pb3BWeUED
1PormUgPR72yv2FRKSVY27U4ekWMKobWjg
14cATAzXwD7CQf35n8Ea5pKJPfhM6jEHak
1PopeZ4LNLanisswLndAJB1QntTF8hpLsD

 

Email Addresses
[email protected][.]com  [email protected][.]li
[email protected][.]ne  [email protected][.]cc 
[email protected][.]me  [email protected][.]com 
[email protected][.]gf  [email protected][.]com 
[email protected][.]com [email protected][.]com 

 

Email Addresses
[email protected][.]com  [email protected][.]com
[email protected][.]com  [email protected][.]com
[email protected][.]com  [email protected][.]com 
[email protected][.]com [email protected][.]com
[email protected][.]com  [email protected][.]me
[email protected][.]com  [email protected][.]com 
[email protected][.]com [email protected][.]com 
[email protected][.]com  [email protected][.]com
[email protected][.]com  [email protected][.]com 
[email protected][.]com [email protected][.]com
[email protected][.]com [email protected][.]com
[email protected][.]cyou [email protected][.]com 
[email protected][.]business [email protected][.]com
[email protected][.]cyou [rescuer]@cock[.]li 
[email protected][.]business [email protected][.]com 
[email protected][.]com [email protected][.]com 
[email protected][.]org  [email protected][.]com
[email protected][.]com [email protected][.]gf
[email protected][.]com [email protected][.]com
[email protected][.]com  [email protected][.]com
[email protected][.]com  [email protected][.]com
[email protected][.]com [email protected][.]org
[email protected][.]com  [email protected][.]io
[email protected][.]com [email protected][.]com 
[email protected][.]com [email protected][.]com 
[email protected][.]com  [email protected][.]com 
[email protected][.]li [email protected][.]lv
[email protected][.]com  [email protected][.]com
[email protected][.]com  [email protected][.]li
[email protected][.]me  [email protected][.]com 

 

Email Addresses
[email protected][.]ma [email protected][.]com
[email protected][.]org [email protected][.]org
[email protected][.]li  [email protected][.]info
[email protected][.]com  [email protected][.]com 
[email protected][.]cyou [email protected][.]com 
[email protected][.]cyoum [email protected][.]com
[email protected][.]business [email protected][.]com

 

TOR Addresses
http://gvlay6u4g53rxdi5.onion/6-iSm1B1Ehljh8HYuXGym4Xyu1WdwsR2Av-6tXiw1BImsqoLh7pd207Rl6XYoln7sId 
http://gvlay6u4g53rxdi5.onion/8-grp514hncgblilsjtd32hg6jtbyhlocr5pqjswxfgf2oragnl3pqno6fkqcimqin
http://gvlay6y4g53rxdi5.onion/21-8P4ZLCsMETPaLw9MkSlXJsNZWdHe0rxjt-XmBgZLWlm5ULGFCOJFuVdEymmxysofwu
http://gvlay6u4g53rxdi5.onion/2l-8P4ZLCsMTPaLw9MkSlXJsNZWdHeOrxjtE9lck1MuXPYo29daQys6gomZZXUImN7Z 
http://gvlay6u4g53rxdi5.onion/21-8P4ZLCsMTPaLw9MkSlXJsNZWdHe0rxjt-DcaE9HeHywqSHvdcIwOndCS4PuWASX8g 
http://gvlay6u4g53rxdi5.onion/21-8P4ZLCsMTPaLw9MkSlXJsNZWdHe0rxjt-kB4rQXGKyxGiLyw7YDsMKSBjyfdwcyxo
http://gvlay6u4g53rxdi5.onion/21-8P4ZLCsMTPaLw9MkSlXJsNZWdHe0rxjt-bET6JbB9vEMZ7qYBPqUMCxOQExFx4iOi 
http://gvlay6u4g53rxdi5. onion/8-MO0Q7O97Hgxvm1YbD7OMnimImZJXEWaG-RbH4TvdwVTGQB3X6VOUOP3lgO6YOJEOW
http://gvlay6u4g53rxdi5.onion/8-gRp514hncgb1i1sjtD32hG6jTbUh1ocR-Uola2Fo30KTJvZX0otYZgTh5txmKwUNe 
http://gvlay6u4g53rxdi5.onion/21-E6UQFCEuCn4KvtAh4TonRTpyHqFo6F6L-OWQwD1w1Td7hY7IGUUjxmHMoFSQW6blg 
http://gvlay6u4g53rxdi5.onion/21-E6UQFCEuCn4KvtAh4TonRTpyHqFo6F6L-uGHwkkWCoUtBbZWN50sSS4Ds8RABkrKy 
http://gvlay6u4g53rxdi5.onion/21-E6UQFCEuCn4KvtAh4TonRTpyHqFo6F6L-Tj3PRnQlpHc9OftRVDGAWUulvE80yZbc 
http://gvlay6u4g53rxdi5.onion/8-Ww5sCBhsL8eM4PeAgsfgfa9lrqa81r31-tDQRZCAUe4164X532j9Ky16IBN9StWTH 
http://gvlay6u4g53rxdi5.onion/21-wIq5kK9gGKiTmyups1U6fABj1VnXIYRB-I5xek6PG2EbWlPC7C1rXfsqJBlWlFFfY
qd7pcafncosqfqu3ha6fcx4h6sr7tzwagzpcdcnytiw3b6varaeqv5yd.onion
http://medusacegu2ufmc3kx2kkqicrlcxdettsjcenhjena6uannk5f4ffuyd.onion/leakdata/paigesmusic-leakdata-closed-part1

 

Disclaimer: Many of these observed IP addresses are several years old and have been historically linked to MedusaLocker ransomware. We recommend these IP addresses be investigated or vetted by organizations prior to taking action, such as blocking.

IP Address Last Observed
195.123.246.138 Nov-2021
138.124.186.221 Nov-2021
159.223.0.9 Nov-2021
45.146.164.141 Nov-2021
185.220.101.35 Nov-2021
185.220.100.249 Sep-2021
50.80.219.149 Sep-2021
185.220.101.146 Sep-2021
185.220.101.252 Sep-2021
179.60.150.97 Sep-2021
84.38.189.52 Sep-2021
94.232.43.63 Jul-2021
108.11.30.103 Apr-2021
194.61.55.94 Apr-2021
198.50.233.202 Apr-2021
40.92.90.105 Jan-2021
188.68.216.23 Dec-2020
87.251.75.71 Dec-2020
196.240.57.20 Oct-2020
198.0.198.5 Aug-2020
194.5.220.122 Mar-2020
194.5.250.124 Mar-2020
194.5.220.124 Mar-2020
104.210.72.161 Nov-2019

 

MITRE ATT&CK Techniques

MedusaLocker actors use the ATT&CK techniques listed in Table 1.

Table 1: MedusaLocker Actors ATT&CK Techniques for Enterprise

Initial Access
Technique Title ID Use
External Remote Services T1133 MedusaLocker actors gained access to victim devices through vulnerable RDP configurations.
Phishing T1566 MedusaLocker actors used phishing and spearphishing to obtain access to victims’ networks.
Execution
Technique Title ID Use
Command and Scripting Interpreter: PowerShell

T1059.001

MedusaLocker actors may abuse PowerShell commands and scripts for execution.
Defense Evasion
Technique Title ID Use
Impair Defenses: Safe Mode Boot

T1562.009

MedusaLocker actors may abuse Windows safe mode to disable endpoint defenses. Safe mode starts up the Windows operating system with a limited set of drivers and services.
Impact
Technique Title ID Use
Data Encrypted for Impact T1486 MedusaLocker actors encrypt data on target systems or on large numbers of systems in a network to interrupt availability to system and network resources.
Inhibit System Recovery T1490 MedusaLocker actors may deny access to operating systems containing features that can help fix corrupted systems, such as backup catalog, volume shadow copies, and automatic repair.

 

Mitigations

  • Implement a recovery plan that maintains and retains multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, and secure location (i.e., hard drive, storage device, or the cloud).
  • Implement network segmentation and maintain offline backups of data to ensure limited interruption to the organization.
  • Regularly back up data and password protect backup copies stored offline. Ensure copies of critical data are not accessible for modification or deletion from the system where the data resides.
  • Install, regularly update, and enable real time detection for antivirus software on all hosts.
  • Install updates for operating systems, software, and firmware as soon as possible.
  • Review domain controllers, servers, workstations, and active directories for new and/or unrecognized accounts.
  • Audit user accounts with administrative privileges and configure access controls according to the principle of least privilege. 
  • Disable unused ports.
  • Consider adding an email banner to emails received from outside your organization.
  • Disable hyperlinks in received emails.
  • Enforce multifactor authentication (MFA).
  • Use National Institute of Standards and Technology (NIST) standards for developing and managing password policies:
    • Use longer passwords consisting of at least 8 characters and no more than 64 characters in length.
    • Store passwords in hashed format using industry-recognized password managers.
    • Add password user “salts” to shared login credentials.
    • Avoid reusing passwords.
    • Implement multiple failed login attempt account lockouts.
    • Disable password “hints”.
    • Refrain from requiring password changes unless there is evidence of password compromise. Note: NIST guidance suggests favoring longer passwords and no longer require regular and frequent password resets. Frequent password resets are more likely to result in users developing password “patterns” cyber criminals can easily decipher.
    • Require administrator credentials to install software.
  • Only use secure networks; avoid using public Wi-Fi networks.
  • Consider installing and using a virtual private network (VPN) to establish secure remote connections.
  • Focus on cybersecurity awareness and training. Regularly provide users with training on information security principles and techniques as well as overall emerging cybersecurity risks and vulnerabilities, such as ransomware and phishing scams.

 
Resources

  • Stopransomware.gov is a whole-of-government approach that gives one central location for ransomware resources and alerts.
  • Resource to mitigate a ransomware attack: CISA-Multi-State Information Sharing and Analysis Center (MS-ISAC) Joint Ransomware Guide
  • No-cost cyber hygiene services: Cyber Hygiene Services and Ransomware Readiness Assessment

Reporting

Contact Information

To report suspicious or criminal activity related to information found in this Joint Cybersecurity Advisory, contact your local FBI field office at www.fbi.gov/contact-us/field-offices. When available, please include the following information regarding the incident: date, time, and location of the incident; type of activity; number of people affected; type of equipment used for the activity; the name of the submitting company or organization; and a designated point of contact. To report incidents and anomalous activity or to request incident response resources or technical assistance related to this threat, contact CISA at [email protected].

Revisions

June 30, 2022: Initial Version

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Malicious Cyber Actors Continue to Exploit Log4Shell in VMware Horizon Systems


Actions to take today:
• Install fixed builds, updating all affected VMware Horizon and UAG systems to the latest versions. If updates or workarounds were not promptly applied following VMware’s release of updates for Log4Shell in December 2021, treat all affected VMware systems as compromised.
• Minimize the internet-facing attack surface by hosting essential services on a segregated demilitarized (DMZ) zone, ensuring strict network perimeter access controls, and implementing regularly updated web application firewalls (WAFs) in front of public-facing services

The Cybersecurity and Infrastructure Security Agency (CISA) and United States Coast Guard Cyber Command (CGCYBER) are releasing this joint Cybersecurity Advisory (CSA) to warn network defenders that cyber threat actors, including state-sponsored advanced persistent threat (APT) actors, have continued to exploit CVE-2021-44228 (Log4Shell) in VMware Horizon® and Unified Access Gateway (UAG) servers to obtain initial access to organizations that did not apply available patches or workarounds.

Since December 2021, multiple threat actor groups have exploited Log4Shell on unpatched, public-facing VMware Horizon and UAG servers. As part of this exploitation, suspected APT actors implanted loader malware on compromised systems with embedded executables enabling remote command and control (C2). In one confirmed compromise, these APT actors were able to move laterally inside the network, gain access to a disaster recovery network, and collect and exfiltrate sensitive data.

This CSA provides the suspected APT actors’ tactics, techniques, and procedures (TTPs), information on the loader malware, and indicators of compromise (IOCs). The information is derived from two related incident response engagements and malware analysis of samples discovered on the victims’ networks.

CISA and CGCYBER recommend all organizations with affected systems that did not immediately apply available patches or workarounds to assume compromise and initiate threat hunting activities using the IOCs provided in this CSA, Malware Analysis Report (MAR)-10382580-1, and MAR-10382254-1. If potential compromise is detected, administrators should apply the incident response recommendations included in this CSA and report key findings to CISA.

See the list below to download copies of IOCs: 

Download the pdf version of this report: [pdf, 483 kb]

Note: this advisory uses the MITRE ATT&CK for Enterprise framework, version 11. See Appendix A for a table of the threat actors’ activity mapped to MITRE ATT&CK® tactics and techniques.

Log4Shell is a remote code execution vulnerability affecting the Apache® Log4j library and a variety of products using Log4j, such as consumer and enterprise services, websites, applications, and other products, including certain versions of VMware Horizon and UAG. The vulnerability enables malicious cyber actors to submit a specially crafted request to a vulnerable system, causing the system to execute arbitrary code. The request allows the malicious actors to take full control of the affected system. (For more information on Log4Shell, see CISA’s Apache Log4j Vulnerability Guidance webpage and VMware advisory VMSA-2021-0028.13.) 

VMware made fixes available in December 2021 and confirmed exploitation in the wild on December 10, 2021.[1] Since December 2021, multiple cyber threat actor groups have exploited [T1190] Log4Shell on unpatched, public-facing VMware Horizon and UAG servers to obtain initial access [TA0001] to networks. 

After obtaining access, some actors implanted loader malware on compromised systems with embedded executables enabling remote C2. These actors connected to known malicious IP address 104.223.34[.]198.[2] This IP address uses a self-signed certificate CN: WIN-P9NRMH5G6M8. In at least one confirmed compromise, the actors collected and exfiltrated sensitive information from the victim’s network. 

The sections below provide information CISA and CGCYBER obtained during incident response activities at two related confirmed compromises.

Victim 1

CGCYBER conducted a proactive threat-hunting engagement at an organization (Victim 1) compromised by actors exploiting Log4Shell in VMware Horizon. After obtaining access, threat actors uploaded malware, hmsvc.exe, to a compromised system. During malware installation, connections to IP address 104.223.34[.]198 were observed. 

CISA and CGCYBER analyzed a sample of hmsvc.exe from the confirmed compromise. hmsvc.exe masquerades as a legitimate Microsoft® Windows® service (SysInternals LogonSessions software) [T1036.004] and appears to be a modified version of SysInternals LogonSessions software embedded with malicious packed code. When discovered, the analyzed sample of hmsvc.exe was running as NT AUTHORITY\SYSTEM, the highest privilege level on a Windows system. It is unknown how the actors elevated privileges. 

hmsvc.exe is a Windows loader containing an embedded executable, 658_dump_64.exe. The embedded executable is a remote access tool that provides an array of C2 capabilities, including the ability to log keystrokes [T1056.001], upload and execute additional payloads [T1105], and provide graphical user interface (GUI) access over a target Windows system’s desktop. The malware can function as a C2 tunneling proxy [T1090], allowing a remote operator to pivot to other systems and move further into a network.

When first executed, hmsvc.exe creates the Scheduled Task [T1053.005], C:\Windows\System32\Tasks\Local Session Updater, which executes malware every hour. When executed, two randomly named *.tmp files are written to the disk at the location C:\Users\<USER>\AppData\Local\Temp\ and the embedded executable attempts to connect to hard-coded C2 server 192.95.20[.]8 over port 4443, a non-standard port [TT571]. The executable’s inbound and outbound communications are encrypted with a 128-bit key [T1573.001].

For more information on hmsvc.exe, including IOCs and detection signatures, see MAR-10382254-1.

Victim 2

From late April through May 2022, CISA conducted an onsite incident response engagement at an organization (Victim 2) where CISA observed bi-directional traffic between the organization and suspected APT IP address 104.223.34[.]198. During incident response, CISA determined Victim 2 was compromised by multiple threat actor groups. 

The threat actors using IP 104.223.34[.]198 gained initial access to Victim 2’s production environment in late January 2022, or earlier. These actors likely obtained access by exploiting Log4Shell in an unpatched VMware Horizon server. On or around January 30, likely shortly after the threat actors gained access, CISA observed the actors using PowerShell scripts [T1059.001] to callout to 109.248.150[.]13 via Hypertext Transfer Protocol (HTTP) [T1071.001] to retrieve additional PowerShell scripts. Around the same period, CISA observed the actors attempt to download [T1105] and execute a malicious file from 109.248.150[.]13. The activity started from IP address 104.155.149[.]103, which appears to be part of the actors’ C2 [TA0011] infrastructure. 

After gaining initial access to the VMware Horizon server, the threat actors moved laterally [TA0008] via Remote Desktop Protocol (RDP) [T1021.001] to multiple other hosts in the production environment, including a security management server, a certificate server, a database containing sensitive law enforcement data, and a mail relay server. The threat actors also moved laterally via RDP to the organization’s disaster recovery network. The threat actors gained credentials [TA0006] for multiple accounts, including administrator accounts. It is unknown how these credentials were acquired. 

After moving laterally to other production environment hosts and servers, the actors implanted loader malware on compromised servers containing executables enabling remote C2. The threat actors used compromised administrator accounts to run the loader malware. The loader malware appears to be modified versions of SysInternals LogonSessions, Du, or PsPing software. The embedded executables belong to the same malware family, are similar in design and functionality to 658_dump_64.exe, and provide C2 capabilities to a remote operator. These C2 capabilities include the ability to remotely monitor a system’s desktop, gain reverse shell access, exfiltrate data, and upload and execute additional payloads. The embedded executables can also function as a proxy. 

CISA found the following loader malware:

  • SvcEdge.exe is a malicious Windows loader containing encrypted executable f7_dump_64.exe. When executed, SvcEdge.exe decrypts and loads f7_dump_64.exe into memory. During runtime, f7_dump_64.exe connects to hard-coded C2 server 134.119.177[.]107 over port 443
  • odbccads.exe is a malicious Windows loader containing an encrypted executable. When executed, odbccads.exe decrypts and loads the executable into memory. The executable attempts communication with the remote C2 address 134.119.177[.]107
  • praiser.exe is a Windows loader containing an encrypted executable. When executed, praiser.exe decrypts and loads the executable into memory. The executable attempts connection to hard-coded C2 address 162.245.190[.]203.
  • fontdrvhosts.exe is a Windows loader that contains an encrypted executable. When executed, fontdrvhosts.exe decrypts and loads the executable into memory. The executable attempts connection to hard-coded C2 address 155.94.211[.]207.
  • winds.exe is a Windows loader containing an encrypted malicious executable and was found on a server running as a service. During runtime, the encrypted executable is decrypted and loaded into memory. The executable attempts communication with hard-coded C2 address 185.136.163[.]104. winds.exe has complex obfuscation, hindering the analysis of its code structures. The executable’s inbound and outbound communications are encrypted with an XOR key [T1573.001].

For more information on these malware samples, including IOCs and detection signatures, see MAR-10382580-1.

Additionally, CISA identified a Java® Server Pages (JSP) application (error_401.js) functioning as a malicious webshell [T505.003] and a malicious Dynamic Link Library (DLL) file:

  • error_401.jsp is a webshell designed to parse data and commands from incoming HTTP requests, providing a remote operator C2 capabilities over compromised Linux and Windows systems. error_401.jsp allows actors to retrieve files from the target system, upload files to the target system, and execute commands on the target system. rtelnet is used to execute commands on the target system. Commands and data sent are encrypted via RC4 [T1573.001]. For more information on error_401.jsp, including IOCs, see [MAR-10382580 2].
  • newdev.dll ran as a service in the profile of a known compromised user on a mail relay server. The malware had path: C:\Users\<user>\AppData\Roaming\newdev.dll. The DLL may be the same newdev.dll attributed to the APT actors in open-source reporting; however, CISA was unable to recover the file for analysis. 

Threat actors collected [TA0009] and likely exfiltrated [TA0010] data from Victim 2’s production environment. For a three week period, the security management and certificate servers communicated with the foreign IP address 92.222.241[.]76. During this same period, the security management server sent more than 130 gigabytes (GB) of data to foreign IP address 92.222.241[.]76, indicating the actors likely exfiltrated data from the production environment. CISA also found .rar files containing sensitive law enforcement investigation data [T1560.001] under a known compromised administrator account.

Note: the second threat actor group had access to the organization’s test and production environments, and on or around April 13, 2022, leveraged CVE-2022-22954 to implant the Dingo J-spy webshell. According to trusted third-party reporting, multiple large organizations have been targeted by cyber actors leveraging CVE-2022-22954 and CVE-2022-22960. For more information on exploitation of CVE-2022-22954 and CVE-2022-22960, see CISA CSA Threat Actors Chaining Unpatched VMware Vulnerabilities for Full System Control.

Incident Response

If administrators discover system compromise, CISA and CGCYBER recommend:

  1. Immediately isolating affected systems. 
  2. Collecting and reviewing relevant logs, data, and artifacts.
  3. Considering soliciting support from a third-party incident response organization that can provide subject matter expertise, ensure the actor is eradicated from the network, and avoid residual issues that could enable follow-on exploitation.
  4. Reporting incidents to CISA via CISA’s 24/7 Operations Center ([email protected] or 888-282-0870). To report cyber incidents to the Coast Guard pursuant to 33 CFR Section 101.305,  contact the U.S. Coast Guard (USCG) National Response Center (NRC) ([email protected] or 800-424-8802). 

CISA and CGCYBER recommend organizations install updated builds to ensure affected VMware Horizon and UAG systems are updated to the latest version.

  • If updates or workarounds were not promptly applied following VMware’s release of updates for Log4Shell in December 2021, treat those VMware Horizon systems as compromised. Follow the pro-active incident response procedures outlined above prior to applying updates. If no compromise is detected, apply these updates as soon as possible.
    • See VMware Security Advisory VMSA-2021-0028.13 and VMware Knowledge Base (KB) 87073 to determine which VMware Horizon components are vulnerable.
    • Note: until the update is fully implemented, consider removing vulnerable components from the internet to limit the scope of traffic. While installing the updates, ensure network perimeter access controls are as restrictive as possible.
    • If upgrading is not immediately feasible, see KB87073 and KB87092 for vendor-provided temporary workarounds. Implement temporary solutions using an account with administrative privileges. Note that these temporary solutions should not be treated as permanent fixes; vulnerable components should be upgraded to the latest build as soon as possible. 
    • Prior to implementing any temporary solution, ensure appropriate backups have been completed. 
    • Verify successful implementation of mitigations by executing the vendor supplied script Horizon_Windows_Log4j_Mitigations.zip without parameters to ensure that no vulnerabilities remain. See KB87073 for details. 

Additionally, CISA and CGCYBER recommend organizations:

  • Keep all software up to date and prioritize patching known exploited vulnerabilities (KEVs)
  • Minimize the internet-facing attack surface by hosting essential services on a segregated DMZ, ensuring strict network perimeter access controls, and not hosting internet-facing services non-essential to business operations. Where possible, implement regularly updated WAFs in front of public-facing services. WAFs can protect against web based exploitation using signatures and heuristics that are likely to block or alert on malicious traffic.
  • Use best practices for identity and access management (IAM) by implementing multifactor authentication (MFA), enforcing use of strong passwords, and limiting user access through the principle of least privilege.

Contact Information

Recipients of this report are encouraged to contribute any additional information related to this threat.

  • To request incident response resources or technical assistance related to these threats, email CISA at [email protected]. To contact Coast Guard Cyber Command in relation to these threats, email [email protected].
  • To report cyber incidents to the Coast Guard pursuant to 33 CFR Section 101.305  contact the USCG NRC ([email protected] or 800-424-8802).

Resources

  • For more information on Log4Shell, see:
  • See National Security Agency (NSA) and Australian Signals Directorate (ASD) guidance Block and Defend Web Shell Malware for additional guidance on hardening internet-facing systems.

References

[1] VMware Security Advisory VMSA-2021-0028.13
[2] Fortinet’s blog New Milestones for Deep Panda: Log4Shell and Digitally Signed Fire Chili Rootkits

Appendix A: Indicators of Compromise

See MAR-10382580-1 and MAR-10382254-1 and Table 1 for IOCs. See the list below to download copies of these IOCs: 

Table 1: Indicators of Compromise

Type Indicator Description
IP Address 104.223.34[.]198   IP address closely associated with the installation of malware on victims.
92.222.241[.]76  Victim 2 servers communicated with this IP address and sent data to it during a three-week period.
109.248.150[.]13  Actors attempting to download and execute a malicious file from this address.
104.155.149[.]103  Appears to be a part of the actors’ C2 infrastructure. 
Network Port 192.95.20[.]8:80    Same description as IP 192.95.20[.]8, but includes the specific destination port of 80, which was identified in logs and during malware analysis.
1389  This was the most common destination port for Log4Shell exploitation outbound connections.  Multiple unique destination addresses were used for Log4Shell callback.
104.223.34[.]198:443  IP address closely associated to the installation of malware on victims with the specific destination port of 443.
Scheduled Task C:\Windows\System32\Tasks\Local Session Update  Scheduled task created by hmsvc.exe to execute the program hourly.
File Path C:\Windows\Temp\lnk{4_RANDOM_CHARS}.tmp  File created by hmsvc.exe with a random four-character filename.
C:\Windows\Temp\lnk<4_RANDOM_NUMS_CHAR S>.tmp File created by hmsvc.exe with a random four-character filename.

Appendix B: Threat Actor TTPs

See Table 2 for the threat actors’ tactics and techniques identified in this CSA. See the MITRE ATT&CK for Enterprise framework, version 11, for all referenced threat actor tactics and techniques.

Table 2: Tactics and Techniques

Tactic Technique
Initial Access [TA0001] Exploit Public-Facing Application [T1190

Execution [TA0002]

Command and Scripting Interpreter: PowerShell [T1059.001]
Scheduled Task/Job: Scheduled Task [T1053.005]
Persistence [TA0003] Server Software Component: Web Shell [T1505.003]
Defense Evasion [TA0005] Masquerading: Masquerade Task or Service [T1036.004]
Credential Access [TA0006]  
Lateral Movement [TA0008] Remote Services: Remote Desktop Protocol [T1021.001]
Collection [TA0009 Archive Collected Data: Archive via Utility [T1560.001]
Input Capture: Keylogging [T1056.001]
Command and Control [TA0011] Application Layer Protocol: Web Protocols [T1071.001]
Encrypted Channel: Symmetric Cryptography [1573.001]
Ingress Tool Transfer [T1105]
Non-Standard Port [T1571]
  Proxy [T1090]

Disclaimer

© 2021 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation.

Acknowledgements

CISA and CGCYBER would like to thank VMware and Secureworks for their contributions to this CSA.

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