NEW YORK (AP) — CBS News says private investigators found that Washington reporter Sharyl Attkisson's computer was tampered with multiple times last year.

The network said Friday that an intruder, working remotely using Attkisson's accounts, executed commands involving the search and filtering of data. CBS said it is taking further steps to identify the intruder and how that person gained access to her computer.

CBS hired a cybersecurity firm to conduct the analysis. Attkisson, an investigative reporter who has worked at CBS since 1993, said three weeks ago that she felt her computers had been tampered with.