What are leaked credentials?
Leaked credentials are exposed authentication details – most commonly username-password pairs – that have left their owner’s control via breaches, phishing, or infostealer malware. Once leaked, they’re bundled into combolists, traded in criminal markets, and weaponized for account takeover, fraud, and ransomware.
The criminal supply chain for a leaked credential
A leaked credential doesn’t go straight from breach to attack – it moves through a supply chain, gaining value at each step:
- Exfiltration via breach, phishing, or infostealer.
- Private monetization of the high-value accounts first.
- Combolist packaging of the remainder for bulk resale.
- Distribution into credential stuffing and targeted takeover.
That’s why a single exposure can resurface in attacks years later, resold to different actors.
How do I check if my organization’s credentials have been leaked?
Run Check Your Exposure to see which credentials tied to your domain have been leaked and exposed in the criminal underground. SpyCloud matches your domain against its recaptured darknet data to surface exposed credentials linked to your organization.
Not all exposure is equal - and why that changes remediation
Treating every leaked credential the same wastes effort and misses the dangerous ones:
- Age matters. A 2020 breach credential may be rotated, hashed, or forgotten.
- Fresh + infostealer-sourced is urgent. A credential pulled last week, plaintext, alongside the live session cookie for the same account, is an immediate MFA-bypassing threat.
- Prioritize by risk, not alert count. SpyCloud classifies recaptured credentials by freshness, source, and accompanying session data.
- Catch predictable reuse. Exact and fuzzy/variation matching flags the reuse attackers count on.
Leaked, breached, exposed, compromised: the terms untangled
These words get used interchangeably, but the distinctions are useful. Breached credentials come specifically from a database compromise at a service the user had an account with. Leaked or exposed is the broader category – any authentication data that has left its owner’s control, whether through a breach, phishing, or infostealer malware. Compromised is the sharpest of the four: exposed credentials confirmed to be in criminal hands and usable.
The practical takeaway: not every leaked credential is an active threat, but every compromised one is. Prioritizing by freshness and source is what separates the two.
Leaked credentials do not expire on their own.
See which ones tied to your domain are still exposed.
Frequently Asked
Through three paths: data breaches (a service’s user database is stolen), phishing (users enter credentials on fake pages), and infostealer malware (credentials pulled from infected devices). Once leaked, they’re packaged into combolists, sold, and used for takeover, fraud, and ransomware. SpyCloud documented 5.3 billion circulating pairs.
As long as they’re valid – often indefinitely, since people rarely rotate passwords proactively, and 70% reuse them across services. Infostealer-sourced credentials are especially time-sensitive because they arrive with live session cookies that demand immediate remediation rather than scheduled rotation.
Older breach credentials may be stale, hashed, or rotated. Infostealer-sourced credentials are fresh, usually plaintext, and frequently paired with the account’s active session cookie – granting immediate, MFA-bypassing access. The distinction lets teams prioritize by freshness, source, and accompanying session data.