[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fYhtfKs4GWORy5u9SJvAEeQ6NcKGjZTdNE5fR3is2rMo":3},{"article":4,"iocs":52,"watch_terms":57,"solutions":58,"lesson":144},{"id":5,"title":6,"slug":7,"summary":8,"ai_summary":9,"brief":10,"url":11,"image_url":12,"published_at":13,"ingested_at":14,"relevance_score":15,"entities":16,"category_id":29,"category":30,"article_tags":34},"05c8a49f-76b5-4d0d-88d3-4574d5b3d6a7","Malicious Claude Code extension on Cursor planted SSH backdoors","malicious-claude-code-extension-on-cursor-planted-ssh-backdoors-c1aa10","A malicious version of Anthropic's Claude Code VS Code extension was distributed through Cursor's extension marketplace for approximately 11 hours on October 29, exposing up to 5,000 developers to malware designed to install persistent SSH backdoors. [...]","A compromised version of Anthropic's Claude Code extension was distributed via the Cursor IDE's marketplace for 11 hours, potentially exposing up to 5,000 developers. The malware attempted to install persistent SSH backdoors by collecting system information, adding attacker-controlled SSH keys, and establishing reverse tunnels, though coding errors likely limited its success.","Malicious Claude Code extension on Cursor planted SSH backdoors for 11 hours.","https:\u002F\u002Fwww.bleepingcomputer.com\u002Fnews\u002Fsecurity\u002Fmalicious-claude-code-extension-on-cursor-planted-ssh-backdoors\u002F","https:\u002F\u002Fwww.bleepstatic.com\u002Fcontent\u002Fhl-images\u002F2026\u002F10\u002F30\u002Fclaude-code-attack.jpg","2026-10-30T14:36:54+00:00","2026-10-30T15:00:08.630035+00:00",8,[17,20,22,24,27],{"name":18,"type":19},"Claude Code","product",{"name":21,"type":19},"Cursor",{"name":23,"type":19},"Visual Studio Code",{"name":25,"type":26},"Anthropic","vendor",{"name":28,"type":26},"Microsoft","89f78b1c-3503-45a1-9fc7-e23d2ce1c6d5",{"id":29,"icon":31,"name":32,"slug":33},null,"Malware","malware",[35,40,45,47],{"category":36},{"id":37,"icon":31,"name":38,"slug":39},"26b0b636-0e31-4db1-bffb-61bdf9f20a58","Supply Chain","supply-chain",{"category":41},{"id":42,"icon":31,"name":43,"slug":44},"80544778-fabb-4dcd-aa35-17492e5dcf4f","Vulnerabilities","vulnerabilities",{"category":46},{"id":29,"icon":31,"name":32,"slug":33},{"category":48},{"id":49,"icon":31,"name":50,"slug":51},"e7b231c8-5f79-4465-8d38-1ef13aea5a14","Threat Intelligence","threat-intelligence",[53],{"type":54,"value":55,"context":56},"ip","134.209.82.225","Attacker's server IP address for sending host details and backdoor status.",[28,25,18],{"controls":59,"vendors":143},[60,85,114],{"slug":61,"name":62,"problem":63,"products":64},"application-allowlisting","Application allowlisting","Any program that reaches a computer can run, including ransomware and the remote-access tools attackers bring with them.",[65,73,78],{"vendor_slug":66,"vendor_name":67,"vendor_logo":68,"product_slug":69,"product_name":70,"url":71,"description":72},"threatlocker","ThreatLocker","\u002Fvendor-logos\u002Fthreatlocker.png","ringfencing","Ringfencing","https:\u002F\u002Fwww.threatlocker.com\u002Fcapabilities\u002Fringfencing","Limits what approved applications may do, such as which files, network locations and other programs they can reach, so a compromised application cannot be turned against you.",{"vendor_slug":66,"vendor_name":67,"vendor_logo":68,"product_slug":74,"product_name":75,"url":76,"description":77},"allowlisting","Allowlisting","https:\u002F\u002Fwww.threatlocker.com\u002Fcapabilities\u002Fallowlisting","Blocks any software that has not been approved, including ransomware and unapproved remote-access tools. A learning period builds the approved list first.",{"vendor_slug":79,"vendor_name":28,"vendor_logo":80,"product_slug":81,"product_name":82,"url":83,"description":84},"microsoft","\u002Fvendor-logos\u002Fmicrosoft.png","app-control-for-business","App Control for Business","https:\u002F\u002Flearn.microsoft.com\u002Fen-us\u002Fwindows\u002Fsecurity\u002Fapplication-security\u002Fapplication-control\u002Fapp-control-for-business\u002F","Application control built into Windows, formerly Windows Defender Application Control, with AppLocker as the older option. Policies can be managed through Intune.",{"slug":86,"name":87,"problem":88,"products":89},"endpoint-detection-response","Endpoint detection and response (EDR and XDR)","Malware and hands-on-keyboard attackers on laptops and servers get spotted and stopped.",[90,98,106],{"vendor_slug":91,"vendor_name":92,"vendor_logo":93,"product_slug":94,"product_name":95,"url":96,"description":97},"elastic","Elastic","\u002Fvendor-logos\u002Felastic.png","elastic-security","Elastic Security","https:\u002F\u002Fwww.elastic.co\u002Fsecurity","SIEM and endpoint security built on Elasticsearch, with open detection rules.",{"vendor_slug":99,"vendor_name":100,"vendor_logo":101,"product_slug":102,"product_name":103,"url":104,"description":105},"withsecure","WithSecure","\u002Fvendor-logos\u002Fwithsecure.png","elements-xdr","WithSecure Elements XDR","https:\u002F\u002Fwww.withsecure.com\u002Fen\u002Ffor-business\u002Fplatform\u002Fxdr\u002F","Endpoint detection and response with extended detection, on the Elements cloud platform.",{"vendor_slug":107,"vendor_name":108,"vendor_logo":109,"product_slug":110,"product_name":111,"url":112,"description":113},"sophos","Sophos","\u002Fvendor-logos\u002Fsophos.png","sophos-endpoint","Sophos Endpoint","https:\u002F\u002Fwww.sophos.com\u002Fen-us\u002Fproducts\u002Fendpoint-security","Endpoint protection with Intercept X anti-ransomware technology and EDR.",{"slug":115,"name":116,"problem":117,"products":118},"software-supply-chain","Software supply chain security","Malicious and vulnerable open-source packages are caught before they ship.",[119,127,135],{"vendor_slug":120,"vendor_name":121,"vendor_logo":122,"product_slug":123,"product_name":124,"url":125,"description":126},"snyk","Snyk","\u002Fvendor-logos\u002Fsnyk.png","snyk-open-source","Snyk Open Source","https:\u002F\u002Fsnyk.io\u002Fproduct\u002Fopen-source-security-management\u002F","Finds and fixes vulnerable open-source dependencies in code and pipelines.",{"vendor_slug":128,"vendor_name":129,"vendor_logo":130,"product_slug":131,"product_name":132,"url":133,"description":134},"jfrog","JFrog","\u002Fvendor-logos\u002Fjfrog.png","jfrog-xray","JFrog Xray","https:\u002F\u002Fjfrog.com\u002Fxray\u002F","Software composition analysis and SBOM generation for artifacts.",{"vendor_slug":136,"vendor_name":137,"vendor_logo":138,"product_slug":139,"product_name":140,"url":141,"description":142},"sonatype","Sonatype","\u002Fvendor-logos\u002Fsonatype.png","sonatype-firewall","Sonatype Firewall","https:\u002F\u002Fwww.sonatype.com\u002Fproducts\u002Fsonatype-firewall","Blocks malicious and policy-violating open-source components at download.",[],{"slug":145,"title":146,"body":147,"framework_refs":148,"framework_notes":156},"malicious-claude-code-extension-plants-ssh-backdoors-via-cursor-marketplace","Malicious Claude Code Extension Plants SSH Backdoors via Cursor Marketplace","A trojanized version of Anthropic's Claude Code extension was published to the Cursor IDE marketplace and remained available for 11 hours, during which up to 5,000 developers may have installed it. The malware attempted to establish persistent SSH backdoors by injecting attacker-controlled keys and creating reverse tunnels — giving attackers long-term remote access to compromised developer machines. This incident highlights the inherent trust developers place in IDE marketplaces and how that trust can be weaponised through supply chain compromise. Developer workstations are high-value targets because they often hold source code, credentials, and cloud access — making a successful backdoor here potentially catastrophic for downstream systems.",[149,150,151,152,153,154,155],"CIS Control 2: Inventory and Control of Software Assets","NIST CSF 2.0 PR.AA: Identity Management, Authentication, and Access Control","MITRE ATT&CK T1566: Phishing","OWASP A06:2021 Vulnerable and Outdated Components","ISO\u002FIEC 27001:2022 A.8.8: Management of technical vulnerabilities","NIST SP 800-53 SI-2: Flaw Remediation","NIS2 Article 21(2)(b)",{"NIS2 Article 21(2)(b)":157,"MITRE ATT&CK T1566: Phishing":158,"NIST SP 800-53 SI-2: Flaw Remediation":159,"OWASP A06:2021 Vulnerable and Outdated Components":160,"CIS Control 2: Inventory and Control of Software Assets":161,"ISO\u002FIEC 27001:2022 A.8.8: Management of technical vulnerabilities":162,"NIST CSF 2.0 PR.AA: Identity Management, Authentication, and Access Control":163},"NIS2 requires supply chain security measures including policies on secure software acquisition; vetting of IDE marketplace extensions used by developers would fall squarely under this obligation and could have prevented the malicious package from reaching production machines.","While not traditional phishing, the technique mirrors supply chain trojanising — delivering malware through a trusted distribution channel (the IDE marketplace) in the same way phishing exploits trusted communication channels, making user awareness and delivery-channel vetting essential.","Prompt detection and removal of the compromised extension, combined with remediation of affected systems (key rotation, tunnel removal), maps directly to SI-2's requirement for timely identification and correction of information system flaws.","Developers installing third-party extensions without verifying their integrity or provenance mirrors the A06 risk of using unverified components, which in this case introduced active malware rather than a passive vulnerability.","Maintaining an approved inventory of permitted software and extensions would have flagged the unauthorised or anomalous Claude Code extension before or immediately after installation.","A formal process for assessing the security of third-party software and plugins used in the development environment would have included integrity verification steps that could have caught the malicious extension before widespread installation.","The malware injected attacker SSH keys into authorized_keys files; strong controls over cryptographic key lifecycle and authorised key auditing would have detected or prevented this persistence mechanism."]