The notorious cybercrime group known as FIN7 has diversified its initial access vectors to incorporate software supply chain compromise and the use of stolen credentials, new research has revealed.

"Data theft extortion or ransomware deployment following FIN7-attributed activity at multiple organizations, as well as technical overlaps, suggests that FIN7 actors have been associated with various ransomware operations over time," incident response firm Mandiant said in a Monday analysis.

The cybercriminal group, since its emergence in the mid-2010s, has gained notoriety for large-scale malware campaigns targeting the point-of-sale (POS) systems aimed at restaurant, gambling, and hospitality industries with credit card-stealing malware.

FIN7's shift in monetization strategy towards ransomware follows an October 2021 report from Recorded Future's Gemini Advisory unit, which found the adversary setting up a fake front company named Bastion Secure to recruit unwitting penetration testers in a lead up to a ransomware attack.

Then earlier this January, the U.S. Federal Bureau of Investigation (FBI) issued a Flash Alert warning organizations that the financially motivated gang was sending malicious USB drives (aka BadUSB) to U.S. business targets in the transportation, insurance, and defense industries to infect systems with malware, including ransomware.

Recent intrusions staged by the actor since 2020 have involved the deployment of a vast PowerShell backdoor framework called POWERPLANT, continuing the group's penchant for using PowerShell-based malware for its offensive operations.

"There is no doubt about it, PowerShell is FIN7's love language," Mandiant researchers said.

In one of the attacks, FIN7 was observed compromising a website that sells digital products in order to tweak multiple download links to make them point to an Amazon S3 bucket hosting trojanized versions that contained Atera Agent, a legitimate remote management tool, which then delivered POWERPLANT to the victim's system.

The supply chain attack also marks the group's evolving tradecraft for initial access and the deployment of first-stage malware payloads, which have typically centered around phishing schemes.

Other tools used by the group to facilitate its infiltrations include EASYLOOK, a reconnaissance utility; BOATLAUNCH, a helper module designed to bypass Windows AntiMalware Scan Interface (AMSI); and BIRDWATCH, a .NET-based downloader employed to fetch and execute next-stage binaries received over HTTP.

"Despite indictments of members of FIN7 in 2018 and a related sentencing in 2021 announced by the U.S. Department of Justice, at least some members of FIN7 have remained active and continue to evolve their criminal operations over time," Mandiant researchers said.

"Throughout their evolution, FIN7 has increased the speed of their operational tempo, the scope of their targeting, and even possibly their relationships with other ransomware operations in the cybercriminal underground."