The United States Department of Energy notified employees via an email Wednesday that hackers gained personal information , such as names and social security numbers , of 14,000 current and former agency employees as the result of a hack that occurred in late July . This is the second attack this year that involved a breach of employee data . While the agency said in its memo that no classified data was compromised or targeted , obtaining personally identifiable information is one way that computer hackers use to gain access to computer systems containing critical assets . A spokesperson for the DOE confirmed that it had sent the memo on Wednesday . Cyber attackers were able to access the information by hacking into a human resources system which included information such a payroll data , according to a person familiar with the matter . ;