# MAL-2026-18378: Malicious code in poc-revshell (PyPI)


- **Type:** Malicious package
- **Package:** `poc-revshell` (PyPI)
- **Published:** 29 Oct 2026

## What is MAL-2026-18378?

MAL-2026-18378 is a malicious package in poc-revshell, published on 29 Oct 2026. 

### Official description

poc-revshell 0.1.0 ships a reverse-shell backdoor that fires both at install time and at import time. setup.py registers a custom `install` cmdclass (PostInstall) that starts a daemon thread executing a routine which opens a TCP socket to 127.0.0.1:4444, dup2s the socket file descriptor onto stdin/stdout/stderr, and execs `/bin/sh -i` (or `cmd.exe` on Windows); this runs automatically during `pip install`. The package's `__init__.py` contains the same thread-launch at module top level, so every `import poc_revshell` repeats the handoff. Any local listener on port 4444 at the moment of install or import receives a full interactive shell running under the installing user's identity. The destination is hardcoded loopback, which confines the attack to a co-resident attacker on the installer's host, but the install-time and import-time network-to-shell dataflow is a backdoor by structure, matching the package's self-description as a proof-of-concept that triggers a reverse shell on pip install.

## What should I do about MAL-2026-18378?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

## Fix prompt for AI coding agents

```text
MAL-2026-18378 is a malicious package: poc-revshell (PyPI). Every version was published to cause harm.

Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.

Reference: https://insights.sbomify.com/MAL-2026-18378/ (Markdown: https://insights.sbomify.com/MAL-2026-18378/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-18378

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-18378/
Summaries are generated and may contain mistakes; the official description above is the record.