{"slug": "hackers-are-stealing-claude-tokens-from-subscribers", "title": "Hackers are stealing Claude tokens from subscribers", "summary": "Anthropic has confirmed that hackers are using infostealer malware to steal Claude login sessions and consume subscribers' token allowances, after independent AI consultant Grant de Swardt reported unauthorized usage on his Claude Max 20x account. Anthropic suspended de Swardt's account, invalidated his sessions, and issued a partial refund of £44.49, but the company could not determine how the attacker obtained access. Other users reported similar incidents, with one seeing usage jump from 0% to 100% without their interaction.", "body_md": "On August 4, Grant de Swardt, an independent AI consultant in East Sussex, UK, noticed something strange going on with his Claude Max 20x account. He hadn’t been working that day, yet his token usage was climbing.\n\nThe next day, he disabled everything he had attached to Claude and did not work with it. Token consumption again increased. “In the clearest controlled interval, it increased from 45% to 55% while I performed no work, scheduled Cowork tasks were paused or completed, Dispatch/cloud execution was disabled, and there was no corresponding active local Claude Code task,” de Swardt told TechCrunch.\n\nWhat was eating up his token allowance? He had no idea, so he contacted Anthropic and asked for an itemized list. Anthropic didn’t provide one, but it agreed something was off. It suspended his paid account, invalidated all of his sessions and server-side Claude Code tokens, and issued him a partial refund of £44.49 for the remaining time on his $200-per-month subscription.\n\nThe suspension wreaked havok on his business, he told TechCrunch. His job is to help small and mid-size businesses set up agents — a sort of forward-deployed engineer for hire — for tasks like automatically loading purchase-order data from emails into the accounting software.\n\nAs a sole proprietor, he relies on agents throughout his whole business, too: daily admin tasks, website design, coding. “Like everything is just running through AI these days,” he said.\n\nAfter investigating, Anthropic told de Swardt it found the culprit: A compromised Claude session key was used to mint unauthorized Claude Code OAuth tokens. The company told him the account “appeared to have been used by an unauthorized-looking third-party service to handle activity for other people, but they could not determine how it obtained access,” he told TechCrunch. “They say the evidence is consistent either with credentials/session data being taken without my knowledge, or with the account having been connected to an outside service.”\n\nIn other words, a hacker was able to obtain access to de Swardt’s account and was covertly siphoning off his tokens. Because account support tracks total usage but not itemized usage, even upon request, this kind of theft could have gone on for months undetected.\n\nHe posted his [experience on Reddit](https://www.reddit.com/r/ClaudeAI/comments/1vf6i4y/max_20x_usage_went_from_0_to_100_in_half_an_hour/) and after 80 comments, he discovered he was not alone. One person claimed that their account “was auto-upgraded without my consent, my credit card got charged, and the usage shot from 0% to 100% automatically without me even touching it.” Another saw usage go from 0 and to 49 percent in 12 mins, when all they had used it for was a couple of prompts and web search.\n\nOne Claude user said their account burned through its max tokens every day for three days without them using it at all, and created [a Github report](https://github.com/anthropics/claude-code/issues/82506) about it. Like with the Reddit post, others users shared similar experiences there, too.\n\nTwo of them posted emails from Anthropic where the company had — to its credit — identified and warned them that their tokens were being stolen.\n\n“We have recently become aware of a bad actor that is using common infostealer malware to steal Claude login sessions from people’s computers, then using those login sessions to access Claude accounts and consume their usage,” the email read. Infostealers are a type of malware that installs itself on a user’s computer and steals saved passwords, session data, and login-credentials.\n\nWhen Anthropic saw suspicious activity, it signed the users out, invalidated existing authorizations, issued some refunds and warned them that they may have malware.\n\nThe company also said the malware didn’t come from using Claude itself. Such malware can be picked up from many sources online, from downloading infected software to clicking on infected ads.\n\nAnthropic did not send de Swardt one of those emails. He insists he found no evidence that his computer was compromised, and says he still has no way of determining how hackers gained access.\n\nde Swardt’s Claude account was reinstated after about two weeks. But the difficulty of getting speedy help for the matter, plus the lack of an itemized usage, soured him on Claude. He cancelled his subscription in favor of Cursor and its ability to use multiple models, including more affordable open-source options.\n\nIn his experience, these other models work as well as Claude. “It’s not that much different or better,” he said, adding that he can’t see going back “without them actually having resolved the issue in any way.” He says Anthropic still lacks tools that allows users to see what’s consuming their tokens. “I don’t think there’s any way that these people can protect themselves.”\n\nWhen asked for information on how users can identify misuse, Anthropic declined to comment.", "url": "https://wpnews.pro/news/hackers-are-stealing-claude-tokens-from-subscribers", "canonical_source": "https://techcrunch.com/2026/09/08/hackers-are-stealing-claude-tokens-from-subscribers/", "published_at": "2026-09-08 21:10:27+00:00", "updated_at": "2026-09-08 21:31:17.688557+00:00", "lang": "en", "topics": ["ai-safety", "ai-products"], "entities": ["Anthropic", "Claude", "Grant de Swardt", "TechCrunch", "Reddit", "GitHub"], "alternates": {"html": "https://wpnews.pro/news/hackers-are-stealing-claude-tokens-from-subscribers", "markdown": "https://wpnews.pro/news/hackers-are-stealing-claude-tokens-from-subscribers.md", "text": "https://wpnews.pro/news/hackers-are-stealing-claude-tokens-from-subscribers.txt", "jsonld": "https://wpnews.pro/news/hackers-are-stealing-claude-tokens-from-subscribers.jsonld"}}