A New Framework For Detecting Advanced Rootkits

A pair of security researchers launched a new open-source project last week at Black Hat USA that will make it easier for large organizations to look for persistent and hard-to-detect rootkits on a range of different PC and mobile devices, regardless of the operating system they use.

Released by two researchers from ReversingLabs, the rootkit detection framework is designed to examine Unified Extensible Firmware Interface (UEFI), the increasingly prevalent boot-level firmware successor of BIOS that is used by everything from smartphone and tablet hardware to the latest generation of traditional PCs as a software intermediary between the hardware platform and the device's operating system.

Though UEFI-based devices have mushroomed during the past five years, and even as operating system vendors have been pushed to harden their products by the security community, UEFI protection has largely been left to languish, says Mario Vuksan, founder and CEO of ReversingLabs.

"We have put so much effort into securing the OS level, and for all those successes and failures, there hasn't been much talk at the UEFII level, and there are very few security tools for UEFI and very few debugging, monitoring, and analysis tools, to boot. If this vector becomes really widespread, we're going to have a serious problem globally," Vuksan says, who calls UEFI a "meaty OS" with the capability to access file system, memory, network functions, and more. "Any compromise of the UEFI layer means complete root access to the entire device regardless of what OS you're using and what level of OS protection or encryption you end up using."

Vuksan hopes to improve UEFI protection prospects with the launch of the new open-source Rootkit Detection Framework for UEFI (RDFU), a tool developed under a DARPA Cyber Fast Track grant by Vuksan and his colleague and co-presenter Tomislav Pericin. The framework will give developers the ability to build out UEFI rootkit scanners for all versions of the UEFI specification, giving them the ability to grow with the standard and their needs.

At Black Hat, Vuksan and Pericin showed the effectiveness of RDFU detection mechanisms by bringing forward a proof-of-concept rootkit they developed for Apple OS X that can sniff FileVault passwords and accomplish privilege escalations to root and hide PID, files, and directories on the machine. Their talk demoed how RDFU worked against their proof-of-concept.

The motivation of the project was to offer an easier way to ferret out rootkits, which Vuksan says has been the scourge of endpoint management at many large organizations.

"Rootkits have been the plague for endpoint protection ever since the first day because they were so difficult to eradicate, and frequently rootkit attacks keep coming back. Eventually users have to reinstall the entire system," he says, pointing to large federal agencies that have had to give up on their machines due to rootkit infections by simply throwing the hardware away. "The only meaningful way to protect yourself [from UEFI rootkits] without tools would be to pitch the device and buy a new one, which is certainly nothing that consumers will want to deal with," he says. "And imagine a company having to ditch 10,000 machines -- pretty much everyone has to go on vacation for a few weeks until things are back to normal."

According to ReversingLabs, the source code to RDFU is not yet available, but will be released soon on the company's site.

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