An infostealer worm is malware that combines two behaviors: it steals sensitive data, especially credentials, and it can also self-propagate to reach more systems. Unlike simple password thieves, a worm-like infostealer may move through networks, removable media, or shared environments to copy itself and keep searching for secrets. The goal is often to collect API keys, tokens, session cookies, browser data, cloud credentials, or other machine identity material.
This matters because one infected workstation, build server, or developer laptop can expose far more than a single user account. In real attacks, these tools scan files, configuration folders, shells, and software pipelines for hardcoded or cached secrets. Defenders reduce risk by removing plaintext credentials, using short-lived tokens, central secret management, and monitoring endpoints and CI/CD systems for unusual file access or credential harvesting behavior.