Stealer Logs Fuel Ransomware Attacks by Exposing Credentials and Bypassing MFA

Infostealer malware is fueling ransomware attacks by harvesting credentials and session data, allowing attackers to bypass multi-factor authentication. Researchers estimate infostealers collected 1.8 billion credentials in 2025, an 800% increase over six months. Stolen session cookies, which bypass MFA, are particularly valuable for ransomware operators. The underground economy around trading and validating stolen cookies highlights the industrial scale of this cybercrime pipeline.