STOCKHOLM—A Swedish company that provides server space to WikiLeaks has confirmed that the group's Web site was hit by a cyber attack before it leaked thousands of classified U.S. diplomatic cables.
Internet company Bahnhof's chairman Jon Karlung says WikiLeaks didn't use Bahnhof's servers for the documents leak on Sunday but that traces of the attack could be seen on other servers.
Karlung says a distributed denial of service attack started Sunday afternoon Swedish time and stopped in the evening. It was unclear where the attack came from.
Karlung said Monday that such attacks normally use a virus to prompt several computers to call a site simultaneously to overload it. The virus makes it difficult to stop the attack.