Every major data breach eventually results in stolen credentials being traded or published on dark web forums and paste sites. The question isn't whether your data has ever been exposed — statistically it likely has — but whether your current passwords are still at risk.
What happens after a breach
When a company is breached and password hashes are stolen, attackers crack as many as possible offline. Cracked plaintext passwords, along with email addresses, are then compiled into credential lists and sold on dark web marketplaces. These lists are used for credential stuffing attacks — automated tools that try each username/password combo across hundreds of sites.
How to check if your credentials are exposed
Have I Been Pwned (haveibeenpwned.com)
The most trusted free service for breach checking. Enter your email address to see which breaches it appears in, or check specific passwords using their k-anonymity API — your actual password is never transmitted. Created and maintained by security researcher Troy Hunt, it indexes billions of records from thousands of breaches.
Google Password Checkup
Built into Chrome and Android, this tool checks your saved passwords against known breach databases using privacy-preserving cryptography. Find it in Chrome Settings → Passwords → Check passwords.
Firefox Monitor
Mozilla's breach monitoring service, also powered by Have I Been Pwned data. Offers ongoing alerts when your email appears in new breaches.
⚠️ Avoid paid "dark web monitoring" scams: Many services charge monthly fees to "monitor the dark web" for your data. Most use the same public breach data as the free tools above. Save your money and use haveibeenpwned.com directly.
What to do if your credentials are exposed
- Change the password on the breached service immediately
- If you reused that password anywhere else, change it on every site
- Enable 2FA on the affected account
- Monitor for suspicious activity on connected accounts
- Going forward, use a password manager to ensure every account has a unique password
✅ The permanent fix: Credential stuffing only works when you reuse passwords. If every account has a unique randomly generated password, a breach at one site can never compromise another. Set this up once with a password manager and you're protected permanently.