Adecco data breach

Breach date: 2021-01-03. Added to this index: 2022-05-31. Accounts affected: about 4.3M. Domain: adecco.com.

What happened

In March 2021, news broke of a massive data breach impacting millions of Adecco customers in South America which was subsequently sold on a popular hacking forum. The breach exposed over 4M unique email addresses as well as genders, dates of birth, marital statuses, phone numbers and passwords stored as bcrypt hashes.

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.
  • Genders: The gender or sex recorded on your profile, usually picked from a list at signup, sometimes with a title such as Mr or Ms or a gender identity option beyond male and female.
  • Geographic locations: A general location recorded on your account, such as a country, state, city, postcode or region, either typed in by you or estimated from your IP address.
  • Marital statuses: Your relationship status, such as single, married, de facto, separated, divorced or widowed, collected by insurers, lenders, government forms, dating apps and marketing surveys.
  • Names: Your first name, surname and sometimes middle name or initials, as you gave them when you signed up. It appears in almost every breach because nearly every account asks for it.
  • 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.
  • Phone numbers: Your mobile or landline number, collected at signup for contact, delivery updates, marketing and two-factor codes.

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 Adecco breach?

The Adecco breach exposed Email addresses, Genders, Geographic locations, Marital statuses, Names, Passwords, Phone numbers. About 4.3M accounts were affected.

Was I affected by the Adecco 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 Adecco 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