Detecting Typosquatting Packages

Authorized Use Only: This skill is for defensive software-supply-chain security, package screening, and authorized research. Use the corpus-matching and registry-query techniques here only against registries you are permitted to query at scale and packages you intend to evaluate for your own organization. Mass automated registry scraping may violate registry terms of service.

Overview

Typosquatting is a software-supply-chain attack (MITRE ATT&CK T1195.002 — Supply Chain Compromise: Compromise Software Supply Chain) in which an adversary publishes a malicious package whose name is a near-miss of a popular legitimate package — reqeusts for requests, python-sqlite for sqlite3, crossenv for cross-env. A developer who fat-fingers the name, copies a name from a poisoned tutorial, or trusts an AI-generated dependency list (the "slopsquatting" variant, where models hallucinate package names attackers then register) installs the squat instead. Because most ecosystems execute install-time scripts (postinstall in npm, setup.py/build hooks in PyPI), the payload runs immediately with the developer's privileges.

This skill cover…