Claude Code · Anthropic · Claude · Cursor · SpaceX · Wired
A Supply Chain Attack Put Malicious Anthropic Claude Extensions on Thousands of Devices
Compiled by KHAO Editorial — aggregated from 2 sources. See llms.txt for citation guidance.
◎ Multiple-sources
The AI software-development platform Cursor, which is owned by SpaceX, had a malicious Anthropic Claude Code extension for Windows, macOS, and Linux live in its integrated development environment extension marketplace for roughly 11 hours on Thursday.
Key facts
- The AI software-development platform Cursor, which is owned by SpaceX, had a malicious Anthropic Claude Code extension for Windows, macOS, and Linux live in its integrated development environment
- Cursor published remediation steps on Thursday for the roughly 5,000 affected targets
- But Cursor said in its Thursday security alert that “these malicious versions of the extension were not developed by Anthropic
- A malicious actor used access to Cursor’s marketplace to publish a tampered copy of the Claude Code extension, which they didn’t build or publish
Summary
The tainted extension was designed with a backdoor to give attackers access to victim devices—the type of implant that malicious hackers often use as a stepping stone to deeper control inside a target network. “Everyone was so lucky here, this was potentially a dangerous foothold for an attacker,” says Calum Hall, cofounder and CEO of the detection firm Phorion, the first researchers to spot the malicious extension after detecting it on a customer's Mac. What is still unclear is how the malicious extension made its way into the Cursor marketplace at all. Felix Rieseberg, a member of Anthropic's technical staff, posted on X on Friday: “They're working with Cursor on this incident, but it wasn’t a compromise of Anthropic’s systems or employee laptops.