Learn about how the cutting-edge, free software Heads project detects
BIOS and kernel tampering, all with keys under your control.
Some of the earliest computer viruses attacked the boot sector—that bit
of code at the beginning of the hard drive in the Master Boot Record
that allowed you to boot into your operating system. The reasons for this have
to do with stealth and persistence. Viruses on the filesystem itself
would be erased if users re-installed their operating systems, but
if they didn't erase the boot sector as part of the re-install process,
boot sector viruses could stick around and re-infect the operating system.