This is the question that you should be asking yourself if you have not been diligent in the monitoring your computers. It has been estimated by others in the past that as many as 30% of PC’s that are connected to the Internet are compromised in one way or the other.
SophosLabs raises the question “Did your PC try to bring down the Internet last Night” This is in response to the largest attack on Root DNS servers since 2002 that took place over a 12 hour period on Monday.
If you have been negligent in maintaining your PC’s Security you may find that it is controlled by someone other than you, and may have be part of a large botnet that is used to attack web sites, send spam and cause havoc.
Someday we could wake up to a non functioning Internet due to the carelessness of thousands upon thousands of careless Internet users. Sophos.com