Anthropic automatically signs out Claude users to protect them from hackers

Infostealer malware apparently had harvested active Claude login sessions from users’ PCs. Anthropic automatically signs out Claude users to protect them from hackers. That’s according to an email the company sent to affected users last week, which has since been shared publicly on Reddit.

As reported by SecurityWeek, the AI giant points to customers’ own computers rather than any breach at Anthropic, telling affected users that infostealer malware had harvested active Claude login sessions from their own PCs. Once inside affected accounts, the attacker(s) could burn through usage limits and make unauthorized Claude charges. "If your usage limits looked like they refilled and then drained while you weren’t using Claude, this was likely the cause," the email reads.

In response, Anthropic said it forced sign-outs of affected sessions, removed the card on file and refunded any extra usage charges it tied to the activity. While this stops the stolen sessions, Anthropic told affected users that this doesn’t remove the malware. Both Windows and macOS users are affected Anthropic has identified six malware families as responsible for the hijacked sessions so far: Vidar, Lumma, StealC, RedLine, Acreed on Windows and Atomic Stealer (AMOS) "on a small number of Macs." None of these infostealers has been built to target Claude specifically; they’re general-purpose stealers that usually come bundled with malicious downloads.

Update: Service appears to be coming back online for some after about half an hour. Your mileage may vary.

Multiple models are currently affected. Is Claude down for you? Here’s what’s going on (Update: Back online).

It is apparently not a good day for AI chatbots, as ChatGPT, Claude, and Grok are all down or experiencing issues for many users. OpenAI’s status page acknowledges issues across ChatGPT and Codex, while Grok’s website notes that it is currently experiencing issues as well.

Claude, ChatGPT/Codex, and Grok are currently experiencing what appears to be a widespread outage for many users. IOS 27 fixes Apple Mail in three ways longtime users will love Ryan Christoffel Sep 2 2026.

Here’s what’s going on (Update: Back online). Here’s what’s going on (Update: Back online) Multiple models are currently affected.

Likewise, Anthropic’s status page indicates Claude is experiencing elevated errors. All of the companies are investigating the outages.

The issue affects Mythos 5.1, Fable 5.1, Opus 5, and more. The company says it has identified the issue and is working on a fix.

Update: The chatbots are in the process of coming back online. Tag: ChatGPT This article, " Claude, ChatGPT, and Grok Are Down on iPhone and Web " first appeared on com Discuss this article in our forums.

Update: September 3, 2026 (12:27 PM ET): According to Anthropic, the issue has been resolved and all models are operational again. Original article: September 3, 2026 (10:02 AM ET): Having some trouble with Claude today.

Claude, ChatGPT, and Grok Are Down on iPhone and Web.

You’re far from the only one, as a growing number of users are also reporting issues. Here’s what’s going on with Anthropic’s AI services.