Researchers have discovered one of the first pieces of malware ever used in the wild that modifies the software on the motherboard of infected computers to ensure the infection can't be easily eradicated.
Known as Trojan.Mebromi, the rootkit reflashes the BIOS of computers it attacks to add malicious instructions that are executed early in a computer's boot-up sequence. The instructions, in turn, alter a computer's MBR, or master boot record, another system component that gets executed prior to the loading of the operating system of an infected machine. By corrupting the processes that run immediately after a PC starts, the malware stands a better chance of surviving attempts by antivirus programs to remove it.
Full Story @ The Register
Analysis @ Webroot