Anthropic Claude
Inside a malicious Claude Code-branded extension and its persistent SSH backdoor
At a glance
Low rather than Medium: UK relevance is 40 of 100, little UK-specific signal so far.
Briefing
- Do not treat uncorroborated claims as confirmed breaches.
Next steps
Monitor- For awareness — no fixed action deadline for this reporting
No technical write-up beyond the summary below yet.
Next steps
Monitor- No immediate technical action — track if your estate depends on the products or vendors discussed
Summary
- Microsoft analyses a malicious Claude Code–branded extension, its persistent SSH backdoor, and guidance to detect and remediate it.
Read the original reportMicrosoft Security Blog(opens in a new tab)
Products and services involved
- Anthropic Claude88% match confidence
Pulse
Last change 31 Oct · Recheck overdue since 1 Nov 2026, 02:32 UK time
- Story31 Oct 2026, 02:32 UK time · 31 Oct
Linked reporting from Microsoft Security Blog (research).
Read source (Microsoft Security Blog)
1 entry so far. The timeline chart appears once this story has more history.
Sources
- Microsoft Security BlogResearcher
Inside a malicious Claude Code-branded extension and its persistent SSH backdoor
How we know
Statements extracted from sources. Higher confidence means stronger corroboration.
- ClaimedHeadline60% confidence
Inside a malicious Claude Code-branded extension and its persistent SSH backdoor
- ProbableSummary fact75% confidence
Microsoft analyses a malicious Claude Code–branded extension, its persistent SSH backdoor, and guidance to detect and remediate it. The post Inside a malicious Claude Code-branded extension and its persistent SSH backdoor appeared first on Microsoft Security Blog.