Breach date: 2015-12-14. Added to this index: 2016-12-17. Accounts affected: about 4.9M. Domain: quinstreet.com.
What happened
In approximately late 2015, the maker of "performance marketing products" QuinStreet had a number of their online assets compromised. The attack impacted 28 separate sites, predominantly technology forums such as flashkit.com, codeguru.com and webdeveloper.com (view a full list of sites). QuinStreet advised that impacted users have been notified and passwords reset. The data contained details on over 4.9 million people and included email addresses, dates of birth and salted MD5 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
Dates of birth: Your full birth date, day, month and year, collected at signup for age checks, identity verification, insurance quotes, birthday offers or government services.
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.
IP addresses: The network addresses your devices used when you signed up, logged in or posted, recorded by almost every website in its access logs.
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.
Usernames: The handle or login name you chose for an account, which may be public on forums, games and social platforms or used privately to sign in.
Website activity: Records of your actions on a website or app, such as pages viewed, searches, clicks, downloads, logins, cart activity, IP addresses and timestamps.
What to do now
Check whether your own address is in this dataset with the free email breach check.
Change the password on this service and every other site where you used the same password.
Turn on two-factor authentication on your email account first, because it is the reset path for everything else.
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 QuinStreet breach?
The QuinStreet breach exposed Dates of birth, Email addresses, IP addresses, Passwords, Usernames, Website activity. About 4.9M accounts were affected.
Was I affected by the QuinStreet 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 QuinStreet 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.