Bot software spreads, causes new worries

Bot software sounds a bit like a low-budget horror movie, but it´s quietly making trouble and stealing data right now, using millions of PCs worldwide. These malicious pieces of code, often compared to an undercover army of robots, invade a PC and use its computing power to do someone else´s dirty work - most often without the PC owner´s knowledge. The infected PC, known as a Zombie, becomes another node on a Bot network, typically 2,000 to 10,000 PCs strong, according to Symantec. Unfortunately, a Bot network proves a practical tool for people who want to spread PC viruses and worms, send spam emails, install spyware on PCs, or carry out denial-of-service attacks on particular Web sites