Researchers Expose TA585’s MonsterV2 Malware Capabilities and Attack Chain
Oct 14, 2025
Malware / Social Engineering
Cybersecurity researchers have shed light on a previously undocumented threat actor called TA585 that has been observed delivering an off-the-shelf malware called MonsterV2 via phishing campaigns. The Proofpoint Threat Research Team described the threat activity cluster as sophisticated, leveraging web injections and filtering checks as part of its attack chains. "TA585 is notable because it appears to own its entire attack chain with multiple delivery techniques," researchers Kyle Cucci, Tommy Madjar, and Selena Larson said . "Instead of leveraging other threat actors – like paying for distribution, buying access from initial access brokers, or using a third-party traffic delivery system – TA585 manages its own infrastructure, delivery, and malware installation." MonsterV2 is a remote access trojan (RAT), stealer, and loader, which Proofpoint first observed being advertised on criminal forums in February 2025. It's worth noting that MonsterV2 is also calle...