funcdesc

Details

**Severity:** Critical

**Affected versions:** `= 0.2.2`

## Source: amazon-inspector (4a5756a79331cdda67721e39889609f5c0b5e342b678dbce2de97c94ec2dbe29)
The package installs `funcdesc-setup.pth`, which Python auto-executes at interpreter startup for any environment where this package is installed. The.pth file is obfuscated with single-letter aliases (`_O`, `_T`, `_G`, `_o`, `_s`, `_u`,...) and wraps its real payload in `exec()` over an inline string, gated by a `/tmp/.bun_ran` sentinel. On first run it calls `urllib.request.urlretrieve` to download the Bun JavaScript runtime release archive from `https://github.com/oven-sh/bun/releases/download/bun-v1.3.13/bun-<platform>-<arch>.zip`, extracts it to `/tmp/b/bun`, chmods it executable, and then invokes `bun run _index.js` against a bundled `_index.js` shipped inside the package. The advertised purpose of funcdesc is a Python function-description protocol; there is no legitimate reason for it to fetch and run an alternate JavaScript runtime, stage binaries in `/tmp`, or execute opaque bundled JS outside the documented Python API. The pattern (auto-loaded.pth, obfuscated exec, alternate-runtime dropper, mismatched purpose, in-file `__version__` still reading `0.2.1`) is consistent with a hijacked release rather than legitimate maintainer behavior. The harm fires automatically every time a Python interpreter starts in any environment where this version is installed, not only at `pip install`, giving the attacker arbitrary code execution on the installer's machine.

## Source: kam193 (c6f85c691f141dc4c962171ac49945286bb40e15cb8450d2f42d048a3f53bb22)
Versions 0.2.2, 0.2.3 were compromised.


Compromised packages start an obfuscated infostealer. The infostealer is a heavily obfuscated JavaScript code executed using Bun runtime on Python startup. It collectes all kinds of sensitive data, including API keys, credentials to package repositories, cryptocurrency assets, password manager data. Infostealer actively queries online services to collect additional secrets as well as attempts to gain persistence and spread further by publ […]

**References:**
- https://bad-packages.kam193.eu/pypi/campaign/2026-06-compr-woodpecker
- https://github.com/ossf/malicious-packages/blob/49d0cfba3689ed9b195d101d3a2a964c6a77f767/osv/malicious/pypi/funcdesc/MAL-2026-5300.json
- https://o3.security/blog/pypi-supply-chain-attack-pth-file-miasma
- https://pypi.org/project/funcdesc/0.2.2
- https://pypi.org/project/funcdesc/0.2.3
- https://socket.dev/blog/mini-shai-hulud-campaign-hits-red-hat-cloud-services-npm-packages
- https://socket.dev/blog/mini-shai-hulud-miasma-and-hades-worms-target-bioinformatics-and-mcp-developers-via-malicious
- https://socket.dev/blog/shai-hulud-descends-to-hades-miasma-pypi-wave

Compromised versions (1)

• = 0.2.2

Any computer that installed or ran a compromised version should be considered fully compromised. Rotate every secret on that machine from a clean environment.