Excuse me sir: there's a rootkit in your master boot record

Security mavens have uncovered a new class of attacks that attach malware to the bowels of a hard drive, making it extremely hard to detect and even harder to remove.

The rootkit modifies a PC's master boot record (MBR), which is the first sector of a storage device and is used to help a PC locate an operating system to boot after it is turned on. The result: the rootkit is running even before Windows loads. There have been more than 5,000 infections in less than a month, researchers say.