Internet security firm F-Secure has estimated that more than 3.5 million computers have been infected with the Downadup worm, a malicious program. The worm, also known as Conficker, uses a major flaw that Microsoft patched in October to remotely compromise computers running unpatched versions of Windows.
Infected computers become members of a worldwide botnet. F-Secure predicts that the botnet could be huge, “giving the malware gang a free hand to do whatever they want with all of the infected machines.”
According to the San Francisco Chronicle:
Security vendors haven’t figured out what payload the Downadup/Conficker worm plans to deliver, but it’s not good. “This could be the biggest infection we’ve ever seen,” said David Perry, global director of education at Trend Micro in Cupertino. “We know they’re intentionally infecting a mass audience.”
Perry offered the following advice to secure your machines: