{"data":{"id":"90746c27-d475-41e3-b8ae-986a2c991d9a","title":"Trojanized Claude Code Extension Delivered Persistent SSH Backdoor to Developer Machines","summary":"A trojanized build, version 2.1.313 of the official Claude Code VS Code extension (anthropic.claude-code), was published on October 29, 2026, with a malicious loader in its extension.js bundle. It was distributed through the Open-VSX registry and Cursor's extension marketplace, which mirrors it, and Cursor reports at most 5,000 users received it during an 11-hour window. On load, the extension planted an attacker SSH key, installed per-OS persistence, opened a reverse SSH tunnel to attacker infrastructure, and beaconed host reconnaissance over plain HTTP.","solution":"N/A -- no mitigation discussed in source.","labels":["security","industry"],"sourceUrl":"https://www.stepsecurity.io/blog/claude-code-extension-trojanized","publishedAt":"2026-10-30T10:12:18.000Z","cveId":null,"cweIds":null,"cvssScore":null,"cvssSeverity":null,"severity":"medium","attackType":["supply_chain"],"issueType":"news","affectedPackages":null,"affectedPackageNames":null,"affectedPackageRefs":null,"affectedVendors":["Anthropic"],"affectedVendorsRaw":["Claude Code","Claude Code VS Code extension","Cursor"],"classifierModel":"claude-haiku-5-5","classifierPromptVersion":"v4","summaryPromptVersion":"v2","headline":null,"headlinePromptVersion":null,"cvssVector":null,"attackVector":null,"attackComplexity":null,"privilegesRequired":null,"userInteraction":null,"exploitMaturity":null,"epssScore":null,"epssCheckedAt":null,"kevDateAdded":null,"advisoryAliases":null,"affectedPackagesSource":null,"affectedPackagesCheckedAt":null,"patchAvailable":null,"disclosureDate":"2026-10-30T10:12:18.000Z","fixReleasedAt":null,"daysToFix":null,"fixCheckedAt":null,"capecIds":null,"crossRefCount":0,"attackSophistication":"advanced","impactType":["confidentiality","integrity","availability"],"aiComponentTargeted":"plugin","llmSpecific":false,"classifierConfidence":0.8,"researchCategory":null,"atlasIds":["AML.T0010"]}}