Attackers read Yahoo! Mail

The company divulged a “coordinated effort” to breach an undisclosed number of user accounts and notified victims by prompting them to reset their passwords.

“The list of usernames and passwords that were used to execute the attack was likely collected from a third-party database compromise,” Yahoo officials stated in a blog post. “We have no evidence that they were obtained directly from Yahoo’s systems.”

Automated software likely analyzed the list of usernames and passwords to access Yahoo! Mail accounts.

The attackers might have been after the personal information of the victims’ contacts: “The information sought in the attack seems to be names and email addresses from the affected accounts’ most recent sent emails,” Yahoo officials wrote.

ThreatWatch is a regularly updated catalog of data breaches successfully striking every sector of the globe, as reported by journalists, researchers and the victims themselves.