More than 2.2 million Windows PCs in the USA are harbouring botnet malware, making the country the biggest host for zombies in the wired world, a Microsoft report reveals.
The software monopolist said it had cleaned up more than 6.5 million botnet infestations in the first half of 2010, but millions more were lurking undetected. The problem is twice as bad as last year, the outfit's biannual Security Intelligence Report (SIRv9) revealed.
In highly wired South Korea, 14.6 out of every 1,000 machines harbour botnet Zombies, the highest infection percentage in the world. In terms of raw numbers, Brazil comes second behind the US with a proud total of 550,000 infections.
Microsoft harvested the data from the 600 million machines that use its Essentials and Defender software, as well as its update services
Microsoft issued patches for 49 vulnerabilities this month, the outfit's biggest patch-fest yet. A Microsoft executive recently suggested that PCs likely to pass on any infections should be quarantined from the Internet