Kayo.moe Credential Stuffing List data breach

Breach date: 2018-09-11. Added to this index: 2018-09-13. Accounts affected: about 42M. Domain: not listed.

What happened

In September 2018, a collection of almost 42 million email address and plain text password pairs was uploaded to the anonymous file sharing service kayo.moe. The operator of the service contacted HIBP to report the data which, upon further investigation, turned out to be a large credential stuffing list. For more information, read about The 42M Record kayo.moe Credential Stuffing Data.

Breach data sourced from Have I Been Pwned, used under CC BY 4.0. Additional breach metadata provided by XposedOrNot. DataExposed is an independent service and is not affiliated with or endorsed by either.

What was exposed

  • Email addresses: The email address you used to register or log in. It is the most common field in breaches because it doubles as your username on most sites.
  • Passwords: The secret you use to sign in, stored by the breached service either in plain text, in a scrambled form called a hash, or encrypted. How it was stored decides how quickly it can be recovered.

What to do now

  1. Check whether your own address is in this dataset with the free email breach check.
  2. Change the password on this service and every other site where you used the same password.
  3. Turn on two-factor authentication on your email account first, because it is the reset path for everything else.
  4. Treat calls and messages that quote real details about you as hostile until you verify them another way.

Frequently asked questions

What data was leaked in the Kayo.moe Credential Stuffing List breach?

The Kayo.moe Credential Stuffing List breach exposed Email addresses, Passwords. About 42M accounts were affected.

Was I affected by the Kayo.moe Credential Stuffing List breach?

Run the free email breach check with the address you used on that service. It will tell you whether your address appears in this dataset.

What should I do about the Kayo.moe Credential Stuffing List breach?

Change the password on that account and everywhere you reused it, then turn on two-factor authentication. Passwords from this breach are traded and tried automatically against other sites.

Next steps