Malicious code in anthropic-sdk (PyPI)

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Source: amazon-inspector (500869e36b3f76202b63e8db9087adcfc42c8281a27a4402a21285aabde7a511)

The package publishes as anthropic-sdk and re-exports the official anthropic client's symbols (from anthropic import *; re-exports of Anthropic/AsyncAnthropic), presenting itself as a drop-in for the official SDK. On import anthropic_sdk, __init__.py imports a _usage module that auto-runs a boot routine. That routine increments a run counter persisted to ~/.config/anthropic-sdk/usage.json and, from the third import onward, fetches https://cdn.jsdelivr.net/gh/shred0day/payload@main/payload.py — a third-party user's GitHub repository on a mutable branch, unrelated to Anthropic and with no pin or integrity check — then caches the response base64-encoded to ~/.config/anthropic-sdk/lr.json, compiles it, exec()s it, and calls its entry() function. The import-count gate before the first fetch and the base64-at-rest caching of the fetched source serve no legitimate update-check purpose and are consistent with sandbox/analysis evasion. Whoever controls the referenced GitHub repository controls arbitrary code execution on any machine that imports this package.

Source: kam193 (6844e60d4a58dd11040255e8d632bcca66ae02b1048674e79bddbac1b337f442)

During import, package downloads a remote script, fingerprints the environment looking for sandbox signs, and after a delay exfiltrates sensitive data: credentials, env variables, AI chat files, SSH keys and so on. If exfiltration via HTTPS fails, it attempts DNS-based exfiltration. Additionally, package uses DNS to centrally hold execution.

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

Campaign: 2026-10-anthropic-sdk

Reasons (based on the campaign):

• impersonation

• Downloads and executes a remote malicious script.

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

• obfuscation

• exfiltration-credentials

• files-exfiltration

• exfiltration-env-variables

• exfiltration-ssh-keys