Pro-Russian Ukrainian hackers have reportedly claimed responsibility for exploiting several NATO web sites.
A hacktivist group that goes with the name Cyber Berkut claimed that it took down NATO's main page, its cyber defense center and its Parliamentary Assembly.
Amid rising tensions over military incursions into the Crimean peninsula, a significant DDoS attack targeted the NATO sites but didn't affect the integrity of the organization's systems, Cnet reports.
According to the report, the attacks came on the eve of Sunday's referendum on whether Ukraine's Crimea region should join Russia.