A tampered Claude Code extension stayed on the Cursor marketplace for roughly 11-12 hours, affecting up to 5,000 users, and attempted remote access and data theft. Cursor took the marketplace offline; it is still unknown how attackers accessed Anthropic's verified Cursor account.
Anthropic's Visual Studio Code extension on Cursor was reportedly compromised with a backdoor for nearly 12 hours. It is still unknown how attackers accessed Anthropic's verified Cursor account.
Why it matters: A backdoored extension distributed through a verified account could expose developers who installed it during that window.
Written by AI from Ars Technica AI's published text.
Background
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Anthropic's Claude Code extension on Cursor marketplace compromised
Primary source
“It’s still unknown how attackers got access to Anthropic’s verified Cursor account.”
Interpretation or community commentary rather than straight reporting.
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