How did my unique password end up in a breach if that site wasn't hacked?

[Avery18]

I just got a notification that my password was in a data breach, but it's a unique one I only use for that one site. I'm trying to figure out how that could even happen if there wasn't a direct breach of that specific service.

[Luke_R]

That notification hits different when you’re sure the password was unique. In my experience the breach chain often isn’t the site you got the alert from. a vendor you used, a payment processor, or a password manager could leak data, or the creds get cracked from a leaked hash and show up later under something that looks unrelated.

[RobertVG]

Do this now: change the password on that site, turn on two factor authentication if you can, and run a quick malware check on your devices. If you use a password manager, scan for any notes or records that match that site. You can also search Have I Been Pwned to see if the password appears in other breaches.

[Avery_M]

Did you actually enable two factor authentication on that account?

[VioletR]

I once chased a breach rumor for hours and it turned out to be a phishing page that mimicked a login from a service I rarely used. It made me pause and rethink what felt like the real problem, and I ended up focusing on phishing awareness more than the breach itself.