The FBI just announced the largest ever cybercrime investigation to disrupt and dismantle "botnets" and to prosecute some of the ringleaders in these criminal activities. So far, they have identified about 1 million compromised computers across the country. The FBI is working with the CERT Coordination Center at Carnegie Mellon Univ to notify the victim owners of the computers.
So far, the FBI has charged 3 people with cyber crimes as a direct result of this investigation; one hacker in Texas accused of infecting tens of thousands of computers, one hacker in Seattle accused of using botnets to send tens of millions of spam messages and one hacker in Kentucky accused of using botnets to disable other systems.
Note: The FBI will not contact you online and request your personal information. Nor will they offer to clean your computer for you. As word of this investigation gets out, be wary of fraudulent message appearing to come from the FBI or some other agency and offering to "fix" your computer for you. If you receive such a scam, file a complaint online with the Internet Crime Complaint Center or call the nearest FBI office.
A botnet is a network of other people's computers all controlled by a hacker. In a typical botnet setup, the first hacker uses viruses, worms or trojan horses to install malicious software (the bot) on your computer without your knowledge. The hacker builds up the network as large as possible – tens or even hundreds of thousands of compromised computers. He then rents out the right to use his network of hacked computers to the highest bidder. The second hacker sends out the command messages to all the hacked computers telling them to execute their attack. Examples of attacks might be distributed denial of service (flooding the target with so many requests that the real traffic can't get through), publication of phishing emails, click fraud and mass distribution of spam and spyware.
Unfortunately, the hacked computer's user might not even notice that his/her computer is being used by someone else. Look for slow performance, an outbox full of mail you didn't send or messages saying that you've sent spam. Any of these would be reason to investigate your computer carefully.
If you think your computer might be infected, contact your Technical Support immediately.
Take the following steps to protect your computer from being captured in a botnet: