Cthulhu Stealer is a malware family tracked across 2 threat clusters and 1 intelligence report mention on ThreatCluster. First observed November 21, 2025; most recent activity November 21, 2025.
Cthulhu Stealer is a data-stealing malware family that exfiltrates credentials and sensitive information from infected hosts. The article notes a new WhatsApp-based campaign deploying a hijacking worm, specifically targeting cryptocurrency users in Brazil, highlighting evolving propagation techniques and monetization vectors for this family. This underscores the threat of social-messaging–driven campaigns and account/session hijacking in crypto-focused threat activity.
A sophisticated malware campaign in Brazil is exploiting WhatsApp to target cryptocurrency users, deploying a banking trojan named 'Eternidade Stealer.' This malware hijacks devices, steals financial data, and spreads…
A security flaw in WhatsApp allowed researchers to extract phone numbers of 3.5 billion users. The exploit involved systematically checking numbers through the app's discovery feature, revealing profile photos for 57%…