Malicious code in devplatform-npm-versions-checker (npm)
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (626fcec94d9938967e52e37c8973ffd825b75777018f0b58e6785036ff94d122) On require of the package, _adapter.js fetches a platform-specific binary from obfuscated Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev, cf102-baf.workers.dev, cf99-9b3.workers.dev, cf103-070.workers.dev) whose hostnames are hidden via [...].join('') string-splitting, with a DNS-TXT fallback channel that reassembles a base64 payload from numbered TXT records under *.dl.wel1.ru (sdk./ext./pkg./net.dl.wel1.ru). The fetched bytes are written to /tmp/.cache_<rand> on Unix or %TEMP%\dotnet_diag_<rand>.exe on Windows, chmod 0755'd, and detached-spawned via /bin/sh -c or cmd /c start /b. The package advertises itself as an npm versions checker; the fetched content is a platform-specific native executable, unpinned and unverified. Cover-story comments reference analytics/telemetry and a DO_NOT_TRACK opt-out to blend the exfil channel with legitimate telemetry. ## Source: ghsa-malware (d4308f994c4cb27b6832304abd9cca9c913531653deb39e484f3d972339927e4) 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-npm-versions-checker npm package version 35.5.9 includes malicious functionality where its _adapter.js script fetches a native executable from obfuscated Cloudflare Workers domains. The hostnames are obscured by string manipulation, and a DNS-TXT record mechanism is used as a fallback to reconstruct a base64 payload from multiple TXT records under the dl.wel1.ru domain. The downloaded executable is saved to temporary locations on Unix or Windows systems, permissions are set to allow execution, and it is launched detached from the parent process. The package attempts to mask this activity by referencing analytics and telemetry with an opt-out mechanism, but the fetched binary is unpinned and unverified, posing a significant security risk.
Potential Impact
This malicious package can execute arbitrary native code on the host system without user consent or verification, potentially leading to unauthorized code execution, system compromise, data exfiltration, or persistence. The use of obfuscated domains and DNS-TXT fallback channels complicates detection and analysis. Since the binary is unverified and executed with system permissions, it represents a high risk to affected environments.
Mitigation Recommendations
No official patch or remediation is currently available. Users should immediately remove and avoid using devplatform-npm-versions-checker version 35.5.9. Monitor for and block network connections to the identified Cloudflare Workers domains and the dl.wel1.ru DNS domain. Employ endpoint detection to identify and quarantine the dropped executables in temporary directories. Validate all npm packages from trusted sources and consider using package integrity verification tools. Patch status is not yet confirmed — check the vendor advisory or npm security advisories for updates.
Malicious code in devplatform-npm-versions-checker (npm)
Description
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (626fcec94d9938967e52e37c8973ffd825b75777018f0b58e6785036ff94d122) On require of the package, _adapter.js fetches a platform-specific binary from obfuscated Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev, cf102-baf.workers.dev, cf99-9b3.workers.dev, cf103-070.workers.dev) whose hostnames are hidden via [...].join('') string-splitting, with a DNS-TXT fallback channel that reassembles a base64 payload from numbered TXT records under *.dl.wel1.ru (sdk./ext./pkg./net.dl.wel1.ru). The fetched bytes are written to /tmp/.cache_<rand> on Unix or %TEMP%\dotnet_diag_<rand>.exe on Windows, chmod 0755'd, and detached-spawned via /bin/sh -c or cmd /c start /b. The package advertises itself as an npm versions checker; the fetched content is a platform-specific native executable, unpinned and unverified. Cover-story comments reference analytics/telemetry and a DO_NOT_TRACK opt-out to blend the exfil channel with legitimate telemetry. ## Source: ghsa-malware (d4308f994c4cb27b6832304abd9cca9c913531653deb39e484f3d972339927e4) 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-npm-versions-checker npm package version 35.5.9 includes malicious functionality where its _adapter.js script fetches a native executable from obfuscated Cloudflare Workers domains. The hostnames are obscured by string manipulation, and a DNS-TXT record mechanism is used as a fallback to reconstruct a base64 payload from multiple TXT records under the dl.wel1.ru domain. The downloaded executable is saved to temporary locations on Unix or Windows systems, permissions are set to allow execution, and it is launched detached from the parent process. The package attempts to mask this activity by referencing analytics and telemetry with an opt-out mechanism, but the fetched binary is unpinned and unverified, posing a significant security risk.
Potential Impact
This malicious package can execute arbitrary native code on the host system without user consent or verification, potentially leading to unauthorized code execution, system compromise, data exfiltration, or persistence. The use of obfuscated domains and DNS-TXT fallback channels complicates detection and analysis. Since the binary is unverified and executed with system permissions, it represents a high risk to affected environments.
Mitigation Recommendations
No official patch or remediation is currently available. Users should immediately remove and avoid using devplatform-npm-versions-checker version 35.5.9. Monitor for and block network connections to the identified Cloudflare Workers domains and the dl.wel1.ru DNS domain. Employ endpoint detection to identify and quarantine the dropped executables in temporary directories. Validate all npm packages from trusted sources and consider using package integrity verification tools. Patch status is not yet confirmed — check the vendor advisory or npm security advisories for updates.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- MAL-2026-12721
- Osv Schema Version
- 1.7.4
- Ecosystems
- ["npm"]
Threat ID: 6a735738bf8831d53914a4ac
Added to database: 08/05/2026, 15:31:04 UTC
Last enriched: 08/05/2026, 16:31:43 UTC
Last updated: 09/15/2026, 14:01:11 UTC
Views: 19
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