Breach date: 2016-04-12. Added to this index: 2018-11-17. Accounts affected: about 2.0M. Domain: knowncircle.com.
What happened
In approximately April 2016, the "marketing automation for agents and professional service providers" company KnownCircle had a large volume of data obtained by an external party. The data belonging to the now defunct service appeared in JSON format and contained gigabytes of data related to the real estate and insurance sectors. The personal data in the breach appears to have primarily been used for marketing purposes, including logs of emails sent and tracking of gift cards. A small number of passwords for KnownCircle staff were also present and were 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.
Email messages: The content of emails you sent or received, including subject lines, message bodies, attachments and contacts, exposed through a compromised mailbox, an email provider or a company that kept copies.
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.
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.
Physical addresses: Your residential, postal, billing or delivery address, stored by retailers, utilities, banks, government services and almost any company that sends you something.
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 KnownCircle breach?
The KnownCircle breach exposed Email addresses, Email messages, Genders, Names, Passwords, Phone numbers, Physical addresses. About 2.0M accounts were affected.
Was I affected by the KnownCircle 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 KnownCircle 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.