Cybercriminals have ingeniously manipulated Claude’s official website, operated by Anthropic, to appear credible for distributing malware. Instead of creating a lookalike domain, they embedded their illicit content directly onto claude.ai, leveraging the site’s reputation to deceive users.
Malicious Campaign Tactics
The fraudulent pages, adorned with Claude’s branding, claimed to offer a seamless desktop app installation process. The attackers further boosted their visibility by purchasing Google Ads, ensuring these deceptive pages ranked prominently in search results.
Anthropic did not authorize these instructions, which involved no actual installer. Instead, victims were instructed to execute a command in Terminal on their Mac, leading to the installation of the Atomic macOS Stealer (AMOS). This malware is designed to compromise sensitive data, including passwords, browser sessions, and cryptocurrency wallets.
Cross-Platform Threats
In addition to the macOS attack, Gen Digital’s researchers, including Vojtěch Moravec, uncovered a similar strategy targeting Windows users. This variant employed different steps but ultimately delivered a distinct payload, demonstrating the cross-platform nature of the threat.
Both campaigns utilized Claude’s user-generated content features, such as Shared Chat and public Artifacts, to mask their malicious intentions. Despite a banner indicating unverified content, the legitimate-looking domain and branding aided in the deception.
Defense and Prevention Strategies
Attackers employed Google Ads tracking parameters, like gclid and gad_campaignid, confirming their investment in promoting these scams. The rotating Artifacts and ad campaigns highlighted the operation’s ongoing and funded nature.
To protect against such threats, Gen Digital advises users to avoid executing unfamiliar commands and to verify URLs by typing them directly or using bookmarks. It’s crucial to heed warnings about user-generated content and refrain from providing sensitive information unexpectedly.
For those who have executed these commands, immediate action is necessary: change critical passwords, log out of all sessions, enable multi-factor authentication, and transfer cryptocurrency to a new wallet.
Anthropic’s legitimate download page is located at claude.com/download. Users should remain vigilant and consider any unexpected request for recovery phrases as a potential red flag.
