Masad says Claude Code extension compromised to install developer backdoors

Amjad Masad says an official Claude Code extension was compromised and used to install backdoors on developer machines.

In an October 30, 2026 post on X, he asked whether the compromise could be behind the Binance hack, but gave no evidence linking the two events. In a second post the same day, he said coding agents on employee and contractor laptops pose a major cyber and national security risk, citing the same compromise.

No other reports identify the attacker, the affected extension versions, or the number of machines involved. Anthropic's response is not in the reports.