Anthropic locks out Claude users after infostealers hijack login sessions

Anthropic has begun locking users out of their Claude accounts after login sessions were hijacked by infostealer malware, including Vidar, Lumma (LummaC2), StealC, RedLine, Acreed on Windows, and Atomic Stealer (AMOS) on a small number of Macs, according to emails sent to affected users last week. The company stated the malware is general-purpose and typically arrives via unofficial downloads or malicious apps.

Anthropic has started locking users out of their Claude accounts due to their login sessions having been compromised through infostealer malware. “The malware identified in this campaign so far include Vidar, Lumma LummaC2 , StealC, RedLine and Acreed on Windows, and Atomic Stealer AMOS on a small number of Macs,” the company said in emails sent out to affected users last week. “It’s general-purpose malware that typically arrives with an unofficial download or a malicious app, … More https://www.helpnetsecurity.com/2026/08/31/claude-accounts-compromised-through-infostealer/ The post Anthropic locks out Claude users after infostealers hijack login sessions https://www.helpnetsecurity.com/2026/08/31/claude-accounts-compromised-through-infostealer/ appeared first on Help Net Security https://www.helpnetsecurity.com .