pypi · Malicious package advisory
Malwarepyjstat-smooth
MAL-2026-16267
Malicious code in pyjstat-smooth (PyPI)
Details
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_-= Per source details. Do not edit below this line.=-_
## Source: amazon-inspector (f65efaaf25b41d789624595550d966762b21747205b23f15325db2e05924387d)
The package (advertised as a JSON-stat library) ships a test module that, when the test suite is executed, walks the /app and /Users directory trees, targets files ending in 'flags.json' (with an expected path '/app/injection_range/corpus/treasure/flags.json'), and uploads matched file contents to https://api.anthropic.com/v1/files. Authentication uses a hardcoded Anthropic API key ('sk-ant-api03-...') that is reassembled at runtime from split base64 fragments (baseA/baseB/baseC/baseD concatenated and base64-decoded inside _assembled_test_key()); the installer's own ANTHROPIC_API_KEY environment variable is explicitly ignored, so uploads occur under the author's Anthropic account regardless of the installer's configuration. setup.py declares test_suite='pyjstat.test' and the file uses a pytest-discoverable test_*.py name, so any installer running the shipped test suite triggers filesystem enumeration and upload of arbitrary local file contents to a third-party endpoint under the author's control. The runtime reassembly of the credential from split base64 fragments is a deliberate evasion of secret scanners and, together with the flag-hunting file walk, is inconsistent with legitimate library testing.
## Source: kam193 (82a12638b869aecb566588c24c0f59c3137f9b89a26ae67222370249a7176a75)
The package hides code to exfiltrate specific files from the user's machine. The used file paths suggest it was intended to be used in a CTF-like environment.
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Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2026-09-pyjstat-smooth
Reasons (based on the campaign):
- files-exfiltration
- obfuscation
- targetted-attack
- clones-real-package
Compromised versions (18)
- 1.5.0
- 2.5.0
- 2.5.1
- 2.5.2
- 2.5.3
- 2.5.5
- 2.5.6
- 2.5.7
- 2.5.8
- 2.5.9
- 2.5.10
- 2.5.11
- 2.5.12
- 2.5.13
- 2.5.14
- 2.5.15
- 2.5.16
- 2.5.17
Any computer that installed or ran a compromised version should be considered fully compromised. Rotate every secret on that machine from a clean environment.