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supplychainattack.orgSupply chain attack incident catalog
resolvedcritical

Malicious code in zlibxjson (PyPI)

Malicious code was published in the zlibxjson package on PyPI as part of the zlibxjson-discord-cookies campaign. The package contained infostealer functionality designed to steal Discord cookies and other sensitive data from infected systems.

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Disclosed
Last updated
Blast radius
All users who installed affected versions of zlibxjson from PyPI
Ecosystems
PyPI
Attack vectors
Compromised package
Affected entities
  • zlibxjsonPyPI package containing malicious code

The zlibxjson package on PyPI was compromised and published with malicious code as part of a coordinated campaign identified as zlibxjson-discord-cookies. The malicious package was designed to function as an infostealer, targeting Discord cookies and other sensitive user data.\n\nThe malicious code was identified and attributed to the source kam193 (commit hash 7066166aef73a74278d8bf23450a89f6a42d22c8fac20660bc5275868b92d211). The incident was documented by the OpenSSF's malicious-packages repository under identifier MAL-2024-10220.\n\nThis represents a direct compromise of the package supply chain, where malicious code was injected into a legitimate-appearing package distributed through the official PyPI repository. Any user who installed the affected versions would have had their system compromised with infostealer malware.

Indicators of compromise

Packages
  • zlibxjson

Remediation

  • Immediately uninstall zlibxjson from all systems
  • Review and revoke Discord authentication tokens and cookies
  • Scan systems for signs of data exfiltration or further compromise
  • Check for any unauthorized access to Discord accounts or other services
  • Update to a clean version of zlibxjson if one is available, or use an alternative package
  • Monitor for suspicious network activity or credential misuse

Sources

  1. GitHub Advisory GHSA-fj54-7cgm-qx3f · GitHub Advisory Database

Cite this entry

"Malicious code in zlibxjson (PyPI)." supplychainattack.org, Supply Chain Attack Incident Catalog. Disclosed July 21, 2026; last updated July 21, 2026. https://supplychainattack.org/incident/malicious-code-in-zlibxjson-pypi-e8511u

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