Attkisson has been reporting on the federal government's handling of the terrorist attack on a U.S. diplomatic outpost in Benghazi, Libya, last year and the Justice Department's role in Fast and Furious gun-walking operation.
She said she first noticed strange happenings on her home computer including it turning itself on and off at night. She alerted CBS News officials in January who employed cyberinvestigators to do a forensic analysis that found evidence it had been hacked and the perpetrators tried covering their tracks.
Attkisson declined to say what information was accessed saying she didn't want to compromise her ongoing reporting.
"The unauthorized party accessed the CBS computer at my home on multiple occasions, and specifically in December, they used sophisticated methods to cover their tracks, meaning they tried to remove the indications of their previous unauthorized activity," she said. "We're not prepared to talk more about the who's and who did this today, but the intruder is considered highly skilled and used very sophisticated methods."