World's most advanced rootkit penetrates 64-bit Windows
A notorious rootkit that for years has ravaged 32-bit versions of Windows has begun claiming 64-bit versions of the Microsoft operating system as well.
The ability of TDL, aka Alureon, to infect 64-bit versions of Windows 7 is something of a coup for its creators, because Microsoft endowed the OS with enhanced security safeguards that were intended to block such attacks. The rootkit crossed into the 64-bit realm sometime in August, according to security firm Prevx.
According to research published on Monday by GFI Software, the latest TDL4 installation penetrates 64-bit versions of Windows by bypassing the OS's kernel mode code signing policy, which is designed to allow drivers to be installed only when they have been digitally signed by a trusted source. The rootkit achieves this feat by attaching itself to the master boot record in a hard drive's bowels and changing the machine's boot options.