Caterpillars, roaches and worms crawl on a computer, which represents a computer infected by a virus.
Caterpillars, roaches and worms crawl on a computer, which represents a computer infected by a virus. - 
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We've talked about botnets on this program before. It's certainly creepy to think about your computer sneaking around behind your back, carrying out crimes and never telling you about it. But that's what's happening. Some of these botnets are big, like TDL, but there are plenty of smaller ones out there that have gone unnoticed. I'm not saying your computer is on one of them, but it's very much a possibility.

What seems to set TDL apart, however, is how sinister it is. Roel Schouwenberg is senior malware researcher for Kaspersky Lab, which has recently published new information on TDL. He says the code gets written into a part of the computer that isn't routinely checked by anti-malware programs. And it's a part of the PC that fires up even before Windows launches. So by the time you're even looking at things happen on your screen, the botnet commanders have you in their grip.

He says the people, whoever they are, commanding the botnet are not the ones hooking new people up. Instead, they use an affiliate program where secondary actors trick people into clicking on poisoned links or downloading malware. Those secondary actors are then cut in on the action as a reward for growing the numbers. Being that decentralized an operation and being so hard to find on a computer, TDL is going to be a hard botnet to bring down.

Adding to the challenge, Alex Cox of the security company Net Witness says TDL is run both from a central commander AND in a peer-to-peer method. So your secret infected computer could be getting instructions from its boss or its colleague in secret crime.

Also in this program, a new web tool lets British tennis fans decide if they want to hear lots of grunting or no grunting at all with their strawberries this Wimbledon weekend.

Follow John Moe at @johnmoe