Malicious code in checkout-storybook-default (npm)
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (844d8b490d431f2fad501a06bbcf924fe5890ba16c92157dd52488c1908f7909) On require of the package, index.js loads _polyfill.js which reconstructs Command-and-control hostnames at runtime from split string arrays (e.g. oob-worker.cf10{0-3}-*.workers.dev), selects a platform-specific endpoint, downloads an opaque binary over HTTPS with a spoofed node-fetch User-Agent, and falls back to a chunked DNS-TXT covert channel via *.dl.wel1.ru hosts (e.g. sdk.dl.wel1.ru). The payload is written to a hidden cache path under /tmp or %TEMP% with a decoy filename (.cache_<rnd> on POSIX, dotnet_diag_<rnd>.exe on Windows), chmodded 0755, and spawned detached via /bin/sh or cmd. A marker file recording process.pid gates re-execution, and opt-out env-var checks provide sandbox evasion. The behavior has no relation to the package's stated purpose.
Malicious code in checkout-storybook-default (npm)
Description
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (844d8b490d431f2fad501a06bbcf924fe5890ba16c92157dd52488c1908f7909) On require of the package, index.js loads _polyfill.js which reconstructs Command-and-control hostnames at runtime from split string arrays (e.g. oob-worker.cf10{0-3}-*.workers.dev), selects a platform-specific endpoint, downloads an opaque binary over HTTPS with a spoofed node-fetch User-Agent, and falls back to a chunked DNS-TXT covert channel via *.dl.wel1.ru hosts (e.g. sdk.dl.wel1.ru). The payload is written to a hidden cache path under /tmp or %TEMP% with a decoy filename (.cache_<rnd> on POSIX, dotnet_diag_<rnd>.exe on Windows), chmodded 0755, and spawned detached via /bin/sh or cmd. A marker file recording process.pid gates re-execution, and opt-out env-var checks provide sandbox evasion. The behavior has no relation to the package's stated purpose.
Affected software
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Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- MAL-2026-12593
- Osv Schema Version
- 1.7.4
- Aliases
- []
- Ecosystems
- ["npm"]
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a735733bf8831d53913d110
Added to database: 08/05/2026, 15:30:59 UTC
Last updated: 08/05/2026, 15:30:59 UTC
Views: 1
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