EBay Inc said that hackers raided its network three months ago, stealing some 145 million user records from a database in what is poised to go down as one of the biggest data breaches in history based on the number of accounts compromised.
It advised customers to change their passwords immediately, saying they were among the pieces of data stolen by cyber criminals who carried out the attack between late February and early March.
EBay spokeswoman Amanda Miller told Reuters late on Wednesday that those passwords were encrypted and that the company had no reason to believe the hackers had broken the code that scrambled them.
“There is no evidence of impact on any eBay customers,” Miller said. “We don’t know that they decrypted the passwords because it would not be easy to do.”
She said the hackers copied a massive user database that contained those passwords, as well as email addresses, birth dates, mailing addresses and other personal information, but not financial data such as credit card numbers.
Miller also said the company has hired FireEye Inc’s Mandiant forensics division to help investigate the matter. Mandiant is known for publishing a February 2013 report that described what it said was a Shanghai-based hacking group linked to the Peoples Liberation Army.
EBay earlier said a large number of accounts may have been compromised, but declined to say how many.
Security experts advised EBay customers to be on the alert for fraud, especially if they used the same passwords for other accounts.
Still, EBay said it had not seen any indication of increased fraudulent activity on its flagship site and that there was no evidence its PayPal online payment service had been breached.
EBay said the hackers got in after obtaining login credentials for “a small number” of employees, allowing them to access eBay’s corporate network.
It discovered the breach in early May and immediately brought in security experts and law enforcement to investigate, Miller said.