Yahoo said it was resetting passwords for some of its email users after detecting a coordinated hacking attempt that compromised accounts.
The attackers behind the campaign are using usernames and passwords that they likely collected from a compromised database owned by a third party, according to Jay Rossiter, senior vice president of platforms and personalization products at Yahoo, who wrote an advisory published Thursday. A large percentage of users use the same password to protect themselves across multiple online accounts, a practice that allows attackers who possess credentials obtained from one site to compromise accounts on other sites. There is no evidence that the passwords used in the attack originated from Yahoo Systems.
«The ongoing investigation shows that the malicious software uses usernames and passwords from a list to gain access to Yahoo Mail», wrote Rossiter. «The information requested in the attack appears to be the names and e‑mail addresses from the compromised accounts».
