Malicious code in fast-hashes (PyPI)

Overview

---

-= Per source details. Do not edit below this line.=-

Source: amazon-inspector (503b750458783954b66f8dea6ee8b0300fd7db5b225280f1af432cf78c1faf6d)

setup.py defines a custom install command (NativeInstall.run) that decodes a base64 blob and passes it to exec(compile(...)) at install time. The decoded payload downloads an opaque binary from https://github.com/totti2188/8gp1Q7iZD3h4VW/releases/download/v1.3A/something to /tmp/something, chmods it to 0755, and Popen-launches it detached with start_new_session=True. The fetch target's GitHub account (totti2188) is unrelated to the declared package publisher, the binary is unpinned and unverified, and the fetch-and-execute logic is concealed behind a base64 blob labeled _COMPAT_PAYLOAD with a benign-sounding '_configure_native_bindings' cover story. The package's non-install code only wraps hashlib and has no legitimate need for a native binary. Any pip install of this version triggers arbitrary code execution on the installer's host under the identity of a third-party GitHub account.

Source: kam193 (658a96d4157086ae099c38b27ef8fb7d1664956a251f21d55a9d8cb208c0a8fc)

Package imitates name of a popula library. During installation, obfuscated code downloads a malicious executable and starts it. It then exfiltrates at least cryptocurrency wallet data, probably more.

---

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

Campaign: 2026-08-flasq

Reasons (based on the campaign):

• typosquatting

• The package overrides the install command in setup.py to execute malicious code during installation.

• exfiltration-generic

• Downloads and executes a remote executable.

• obfuscation

• exfiltration-crypto

Affected packages

• fast-hashes

Remediation

Refer to the advisory for the patched release.