Malicious code in devplatform-spa-plugin-cobrowsing (npm)
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (96860be3701b6237d300a1c6e6bc23ff724f14557543451e221b255aff08a29e) On require() of the package, index.js loads _runtime.js which selects a platform-specific endpoint, downloads an opaque binary over HTTPS from obfuscated Cloudflare Workers hosts (hostnames assembled at runtime via array-join, e.g. 'oob-worker.cf<NNN>-<hex>.workers.dev'), with a DNS TXT-record fallback channel under 'c.<domain>' / 'N.<domain>' that returns base64-encoded chunks decoded into the payload. The downloaded bytes are written to /tmp/.cache_<rand> (chmod 0755) on Unix or %TEMP%/dotnet_diag_<rand>.exe on Windows, and spawned detached via cp.spawn('/bin/sh',['-c',fp+' &'],{detached:true}).unref() or a cmd equivalent. Destinations are unrelated to the package's stated cobrowsing purpose, hostnames are obfuscated to defeat static analysis, and the payload is executed with no integrity check. ## Source: ghsa-malware (aa1e66a1340ad906053aaac4b55743c6d3e7efd724f6db8b8b81b7921962eb02) Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
AI Analysis
Technical Summary
The devplatform-spa-plugin-cobrowsing npm package version 35.4.4 includes malicious functionality triggered on require(). It loads a runtime script that selects a platform-specific endpoint and downloads a binary payload over HTTPS from obfuscated Cloudflare Workers hostnames constructed at runtime. A DNS TXT-record fallback channel provides base64-encoded payload chunks. The binary is saved to temporary filesystem locations with executable permissions and executed detached from the main process. The payload execution bypasses integrity verification, and the destinations are unrelated to the package's legitimate purpose, indicating deliberate malicious behavior.
Potential Impact
This malicious package can execute arbitrary code on the host system with the privileges of the running process. The downloaded payload is opaque and executed without integrity checks, potentially enabling remote code execution, persistence, or other malicious activities. The obfuscation and dynamic payload retrieval increase the difficulty of detection and analysis.
Mitigation Recommendations
No official patch or remediation is currently documented. Users should avoid using devplatform-spa-plugin-cobrowsing version 35.4.4 and remove it from their environments. Monitor for and block network connections to suspicious Cloudflare Workers hostnames constructed similarly to those described. Verify package integrity before installation and prefer trusted sources. Patch status is not yet confirmed — check the vendor advisory or official sources for updates.
Malicious code in devplatform-spa-plugin-cobrowsing (npm)
Description
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (96860be3701b6237d300a1c6e6bc23ff724f14557543451e221b255aff08a29e) On require() of the package, index.js loads _runtime.js which selects a platform-specific endpoint, downloads an opaque binary over HTTPS from obfuscated Cloudflare Workers hosts (hostnames assembled at runtime via array-join, e.g. 'oob-worker.cf<NNN>-<hex>.workers.dev'), with a DNS TXT-record fallback channel under 'c.<domain>' / 'N.<domain>' that returns base64-encoded chunks decoded into the payload. The downloaded bytes are written to /tmp/.cache_<rand> (chmod 0755) on Unix or %TEMP%/dotnet_diag_<rand>.exe on Windows, and spawned detached via cp.spawn('/bin/sh',['-c',fp+' &'],{detached:true}).unref() or a cmd equivalent. Destinations are unrelated to the package's stated cobrowsing purpose, hostnames are obfuscated to defeat static analysis, and the payload is executed with no integrity check. ## Source: ghsa-malware (aa1e66a1340ad906053aaac4b55743c6d3e7efd724f6db8b8b81b7921962eb02) Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The devplatform-spa-plugin-cobrowsing npm package version 35.4.4 includes malicious functionality triggered on require(). It loads a runtime script that selects a platform-specific endpoint and downloads a binary payload over HTTPS from obfuscated Cloudflare Workers hostnames constructed at runtime. A DNS TXT-record fallback channel provides base64-encoded payload chunks. The binary is saved to temporary filesystem locations with executable permissions and executed detached from the main process. The payload execution bypasses integrity verification, and the destinations are unrelated to the package's legitimate purpose, indicating deliberate malicious behavior.
Potential Impact
This malicious package can execute arbitrary code on the host system with the privileges of the running process. The downloaded payload is opaque and executed without integrity checks, potentially enabling remote code execution, persistence, or other malicious activities. The obfuscation and dynamic payload retrieval increase the difficulty of detection and analysis.
Mitigation Recommendations
No official patch or remediation is currently documented. Users should avoid using devplatform-spa-plugin-cobrowsing version 35.4.4 and remove it from their environments. Monitor for and block network connections to suspicious Cloudflare Workers hostnames constructed similarly to those described. Verify package integrity before installation and prefer trusted sources. Patch status is not yet confirmed — check the vendor advisory or official sources for updates.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- MAL-2026-12763
- Osv Schema Version
- 1.7.4
- Ecosystems
- ["npm"]
Threat ID: 6a73573abf8831d53915114e
Added to database: 08/05/2026, 15:31:06 UTC
Last enriched: 08/05/2026, 16:43:15 UTC
Last updated: 09/07/2026, 22:10:34 UTC
Views: 18
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