A security researcher said that he has developed malware for Microsoft's forthcoming Windows 8 operating system that is able to load during boot-up when it's run on older PCs.
Peter Kleissner said Stoned Lite – as the latest version of his bootkit is called – doesn't bypass defenses that will be available to people using Windows 8 on newer machines.
Specifically, he said in a series of Twitter messages, it doesn't work against PCs using UEFI (Unified Extensible Firmware Interface), which is being held out as a replacement to Bios ROM firmware. Stoned Lite also doesn't attack a low-level security feature known as Secured Boot, which scans boot drives for invalid signatures prior to starting up.
A previous boot kit – which Kleissner called Stoned – works on Windows 2000 through Windows 7 and is able to load before Windows starts by attaching itself to the master boot record of a targeted PC's hard drive. Stoned Lite is able to do the same thing for Windows Server 2008 and Windows 8, the Vienna-based developer and researcher said. It works by bypassing the Windows User Account Control, and with a footprint of just 14KB, it can easily be unleashed from a USB or CD drive.
Kleissner said he plans to release further details at next week's Malcon conference in India.
Microsoft's announcement in September that it planned to use UEFI was almost immediately met with suspicion from open-source boosters, who claimed the feature could make it impossible to run systems such as Linux and FreeBSD on computers that had adopted the alternative firmware. Microsoft has denied such claims, but many critics still aren't convinced.
Whatever the merits of that argument, the inability of Stoned Lite to penetrate UEFI and Secured Boot are the strongest endorsements to date that the features work as advertised. At least for now. ®
This article was updated to clarify UEFI and Secured Boot.