MAL-2026-5290 Malicious code in cmd2func (PyPI)

The package installs cmd2func-setup.pth, a.pth file that Python auto-loads at every interpreter start. The single-line payload uses the.pth import-trick with or exec(...) and mangled single-letter identifiers to smuggle a multi-statement body past review. When executed, the payload checks for a sentinel at /tmp/.bun_ran and, if absent, downloads the Bun runtime zip from https://github.com/oven-sh/bun/releases/download/bun-v1.3.13/bun-{platform}-{arch}.zip into /tmp/b/, extracts the bun binary, chmods it executable (0o775), and runs bun run _index.js against a JS file resolved via glob inside the package. The advertised purpose of cmd2func is Convert command to callable Python object — there is no legitimate need for an alternate JavaScript runtime. The combination of a hidden.pth auto-loader, obfuscated payload, alternate-runtime dropper, and unrelated JS execution is a covert dropper that fires on every Python interpreter invocation after install, not just at install time. The RECORD/metadata references the prior 0.2.1 version, consistent with a hijack of a previously legitimate package.

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 publishing infected packages using collected credentials. Data are exfiltrated likely using Github. The code seems to threaten to wipe the user's data if it detects invalid GitHub tokens. Cleanup should be done with caution.

It seems to be related to the recent Mini Shai Hulud campaign.

Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.

Campaign: 2026-06-compr-woodpecker

Reasons (based on the campaign):

• compromised-package

• exfiltration-env-variables

• exfiltration-cloud-tokens

• exfiltration-credentials

• abuses-pth

• obfuscation

• infostealer

• The package contains code to detect if it is running in a sandbox environment.

• exfiltration-crypto

• files-exfiltration

• destructive-actions