Threat actors are increasingly using fake Microsoft and Google software updates to try to sneak malware on target systems.
The latest example is “HavanaCrypt,” a new ransomware tool that researchers from Trend Micro recently discovered in the wild disguised as a Google Software Update application. The malware’s command and-control (C2) server is hosted on a Microsoft Web hosting IP address, which is somewhat uncommon for ransomware, according to Trend Micro.
Also notable, according to the researchers, is HavanaCrypt’s many techniques for checking if it is running in a virtual environment; the malware’s use of code from open source key manager KeePass Password Safe during encryption; and its use of a .Net function called “QueueUserWorkItem” to speed up encryption. Trend Micro notes that the malware is likely a work-in-progress because it does not drop a ransom note on infected systems.
HavanaCrypt is among a growing number of ransomware tools and other malware that in recent months have been distributed in the form of fake updates for Windows 10, Microsoft Exchange, and Google Chrome. In May, security researchers spotted ransomware dubbed “Magniber” doing the rounds disguised as Windows 10 updates. Earlier this year, researchers at Malwarebytes observed the operators of the Magnitude Exploit Kit trying to fool users into downloading it by dressing the malware as a Microsoft Edge update.
As Malwarebytes noted at the time, fake Flash updates used to be a fixture of Web-based malware campaigns until Adobe finally retired the technology because of security concerns. Since then, attackers have been using fake versions of other frequently updated software products to try to trick users into downloading their malware — with browsers being one of the most frequently abused.
Creating fake software updates is trivial for attackers, so they tend to use them to distribute all classes of malware including ransomware, info stealers, and Trojans, says an analyst with Intel 471 who requested anonymity. “A non-technical user might be fooled by such techniques, but SOC analysts or incident responders will likely not be fooled,” the analyst says.
Security experts have…