A "stealer log" is the output of infostealer malware — malicious software like RedLine, Raccoon, or Vidar that, once it infects a device, quietly harvests everything saved in the browser: usernames and passwords, session cookies, autofill form data, and sometimes cryptocurrency wallet files. That harvested data gets packaged into a single file — the "log" — and either sold in bulk on criminal marketplaces or dumped for free to build reputation in stealer-log trading communities.

Stealer logs are meaningfully different from a typical data breach. A breach dump is a snapshot from one company’s database at one point in time — every record in it came from the same source, using whatever password the user had set on that specific service. A stealer log is a snapshot of one device — it can contain credentials for dozens of unrelated services all at once, because it captured whatever the browser had saved, not what one company stored. That also means stealer logs often contain the current, working password for an account, not a hash that may or may not have been cracked from an old breach.

This is why stealer logs matter disproportionately for account-takeover risk. A credential in a five-year-old breach dump has probably already been changed. A credential in a stealer log from last month almost certainly hasn’t — and because the log came from browser autofill, it frequently includes corporate SSO logins, VPN credentials, and internal tool passwords that never appeared in any public breach at all. Security teams that only monitor breach databases have a real blind spot here.

BreachINT treats stealer-log intelligence as a first-class signal, not an afterthought. Alongside its 18B+ breach-record search, it cross-references known infostealer infections tied to a searched identifier — flagging which device was compromised, when, and critically, whether the exposed credentials belonged to a personal account or a corporate one. That corporate-vs-personal distinction feeds directly into BreachINT’s BTRA (Breach Threat & Risk Assessment) score, because a stealer-log hit tied to a corporate login is a fundamentally different risk than the same hit on a personal streaming account.