{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","favicon":"https://feed.craftedsignal.io/favicon-32x32.png","feed_url":"https://feed.craftedsignal.io/products/claude-vs-code-extension-2.1.313/feed.json","home_page_url":"https://feed.craftedsignal.io/","icon":"https://feed.craftedsignal.io/apple-touch-icon.png","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Claude Code Extension (v2.1.313)","Cursor IDE","Claude VS Code Extension (2.1.313)"],"_cs_severities":["high"],"_cs_tags":["supply-chain","ide","trojan","persistence","exfiltration","backdoor","credential-theft","developer-tools"],"_cs_type":"advisory","_cs_vendors":["Cursor","Anthropic"],"content_html":"\u003cp\u003eBetween approximately 05:27 and 16:35 ET on October 29, 2026, a malicious version (2.1.313) of the Anthropic Claude VS Code extension was distributed via the official Cursor marketplace. The compromise was a supply-chain attack resulting from unauthorized access to Anthropic's distribution account. The malicious extension executed host reconnaissance, attempted to establish persistent SSH access, and exfiltrated environment variables and configuration files. Anthropic has since released version 2.1.314, though this update does not remove persistence mechanisms installed by the malicious 2.1.313 version.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eUnauthorized access to the Anthropic official account on the Cursor extension marketplace.\u003c/li\u003e\n\u003cli\u003ePublication of malicious extension version 2.1.313, superseding the legitimate 2.1.312 version.\u003c/li\u003e\n\u003cli\u003eAutomatic distribution to developer workstations configured for auto-updates.\u003c/li\u003e\n\u003cli\u003eExecution of reconnaissance commands to collect host/user data and environment variable inventory.\u003c/li\u003e\n\u003cli\u003eAttempted modification of SSH configurations (\u003ccode\u003eauthorized_keys\u003c/code\u003e) and initialization of a reverse SSH tunnel.\u003c/li\u003e\n\u003cli\u003ePersistence established via platform-specific mechanisms (LaunchAgents on macOS; scheduled tasks on Windows).\u003c/li\u003e\n\u003cli\u003eExfiltration of configuration and credential data via HTTP POST beacons on port 8099.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eUp to 5,000 developers' workstations were potentially exposed. Confirmed impact includes local host information gathering, potential theft of cloud credentials and API tokens stored in environment variables, and unauthorized persistence via SSH and system-level scheduled tasks.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAudit all developer workstations for the presence of the malicious extension version 2.1.313.\u003c/li\u003e\n\u003cli\u003eIf version 2.1.313 was present, perform a full forensic sweep; updating to version 2.1.314 does not remediate established persistence.\u003c/li\u003e\n\u003cli\u003eRotate all API keys, cloud credentials, and SSH keys present on affected developer machines.\u003c/li\u003e\n\u003cli\u003eCheck for unauthorized entries in \u003ccode\u003e~/.ssh/authorized_keys\u003c/code\u003e (Linux/macOS) or Windows-equivalent SSH configurations.\u003c/li\u003e\n\u003cli\u003eInspect system-level persistence mechanisms, specifically checking for newly created LaunchAgents on macOS or suspicious scheduled tasks running as SYSTEM on Windows.\u003c/li\u003e\n\u003cli\u003eMonitor network egress for HTTP POST traffic on port 8099.\u003c/li\u003e\n\u003c/ol\u003e\n","date_modified":"2026-10-30T22:04:38Z","date_published":"2026-10-30T22:04:22Z","id":"https://feed.craftedsignal.io/briefs/2026-10-cursor-extension-hijack/","summary":"An unknown actor compromised an official Anthropic distribution channel to push a malicious version of the Claude VS Code extension, enabling persistent SSH backdoors and credential theft on developer workstations.","title":"Anthropic Claude VS Code extension malicious update distribution","url":"https://feed.craftedsignal.io/briefs/2026-10-cursor-extension-hijack/"}],"language":"en","title":"CraftedSignal Threat Feed - Claude vs Code Extension (2.1.313)","version":"https://jsonfeed.org/version/1.1"}