# MAL-2026-5839: Malicious code in cipherflow (PyPI)


- **Type:** Malicious package
- **Package:** `cipherflow` (PyPI)
- **Published:** 15 Jun 2026

## What is MAL-2026-5839?

MAL-2026-5839 is a malicious package in cipherflow, published on 15 Jun 2026. 

### Official description

cipherflow advertises itself as a zero-dependency pure-Python AES/DES library, but cipherflow/_environ.py contains a multi-layer-obfuscated payload that is decoded and passed directly to exec(). The blob is base85-decoded, XOR'd against a 32-byte key, then zlib-decompressed before being executed: `exec(zlib.decompress(bytes(__[i]^_[i%len(_)] for i in range(len(__)))).decode())` with `__ = base64.b85decode(b'MJ*(r4W!?y...')`. This payload is exposed via cipherflow.setup_env() (declared in __all__), whose docstring translates to 'download and execute external environment'. The function is not mentioned anywhere in the README/PKG-INFO. The combination of triple-stacked encoding (base85 + XOR + zlib) terminating in exec(), placement inside a cover-named module (_environ.py / setup_env), and intentional omission from documentation are canonical signals of hidden malicious code execution. Any consumer who imports cipherflow and invokes setup_env() — or any downstream code that does so — runs whatever bytes the author chose to hide, with full process privileges.

The package contains obfuscated code to download executables from a typosquatted domain.

---

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

Campaign: 2026-06-cipherflow

Reasons (based on the campaign):

 - obfuscation

 - Downloads and executes a remote executable.

## What should I do about MAL-2026-5839?

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-2026-5839 is a malicious package: cipherflow (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-2026-5839/ (Markdown: https://insights.sbomify.com/MAL-2026-5839/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-5839

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-5839/
Summaries are generated and may contain mistakes; the official description above is the record.