Unknown hackers gained access to the Washington Post's servers for multiple days and stole employees' user names and passwords, the newspaper said today. Company officials are still trying to determine how much data was exposed, the paper said, but it appears that the hackers did not access any information about the paper's subscribers. This is the second time the newspaper's servers have been breached in the past three years.

The company learned of the breach today. As a precaution, all employees have been asked to change their usernames and passwords. Post officials believe the attack may be the work of Chinese hackers, who were implicated in the previous Post hacking incident. News of the intrusion came the same day that Target was reported to have suffered a major attack on Black Friday, potentially exposing the credit card information of millions of customers.