The Iranian nation-state actor known as TA453 has been linked to a new set of spear-phishing attacks that infect both Windows and macOS operating systems with malware.
“TA453 eventually used a variety of cloud hosting providers to deliver a novel infection chain that deploys the newly identified PowerShell backdoor GorjolEcho,” Proofpoint said in a new report.
“When given the opportunity, TA453 ported its malware and attempted to launch an Apple flavored infection chain dubbed NokNok. TA453 also employed multi-persona impersonation in its unending espionage quest.”
TA453, also known by the names APT35, Charming Kitten, Mint Sandstorm, and Yellow Garuda, is a threat group linked to Iran’s Islamic Revolutionary Guard Corps (IRGC) that has been active since at least 2011. Most recently, Volexity highlighted the adversary’s use of an updated version of a Powershell implant called CharmPower (aka GhostEcho or POWERSTAR).
In the attack sequence discovered by the enterprise security firm in mid-May 2023, the hacking crew sent phishing emails to a nuclear security expert at a U.S.-based think tank focused on foreign affairs that delivered a malicious link to a Google Script macro that would redirect the target to a Dropbox URL hosting a RAR archive.
Present within the file is an LNK dropper that kicks off a multi-stage procedure to ultimately deploy GorjolEcho, which, in turn, displays a decoy PDF document, while covertly awaiting next-stage payloads from a remote server.
But upon realizing that the target is using an Apple computer, TA453 is said to have tweaked its modus operandi to send a second email with a ZIP archive embedding a Mach-O binary that masquerades as a VPN application, but in reality, is an AppleScript that reaches out to a remote server to download a Bash script-based backdoor called NokNok.
NokNok, for its part, fetches as many as four modules that are capable of…