Storm-2561 Spreads Trojan VPN Clients via SEO Poisoning to Steal Credentials
Microsoft has disclosed details of a credential theft campaign that employs fake virtual private network (VPN) clients distributed through search engine optimization (SEO) poisoning techniques. "The campaign redirects users searching for legitimate enterprise software to malicious ZIP files on attacker-controlled websites to deploy digitally signed trojans that masquerade as trusted VPN clients while harvesting VPN credentials," the Microsoft Threat Intelligence and Microsoft Defender Experts teams said . The Windows maker, which observed the activity in mid-January 2026, has attributed it to Storm-2561 , a threat activity cluster known for propagating malware through SEO poisoning and impersonating popular software vendors since May 2025. The threat actor's campaigns were first documented by Cyjax, highlighting the use of SEO poisoning to redirect users searching for software programs from companies like SonicWall, Hanwha Vision, and Pulse Secure (now Iva...