A company that performs background checks for the U.S. Department of Homeland Security said on Wednesday it was the victim of a cyber attack, adding in a statement that "it has all the markings of a state-sponsored attack." The computer breach at Falls Church, Virginia-based US Investigations Services (USIS) probably involved the theft of personal information about DHS employees, according to the Washington Post, which first reported the story. A "multi-agency cyber response team is working with the company to identify the scope of the intrusion," DHS spokesman Peter Boogaard said in a statement. The Office of Personnel Management had also suspended work with USIS, the Post said, adding that government officials do not believe the breach has affected non-DHS employees. "We are working collaboratively with OPM and DHS to resolve this matter quickly and look forward to resuming service on all our contracts with them as soon as possible," USIS said in the statement on its website. Click here to read full news..