Both Kaspersky and Symantec have uncovered another piece of malware that seems to be a government design:

The malware — known alternatively as “ProjectSauron” by researchers from Kaspersky Lab and “Remsec” by their counterparts from Symantec — has been active since at least 2011 and has been discovered on 30 or so targets. Its ability to operate undetected for five years is a testament to its creators, who clearly studied other state-sponsored hacking groups in an attempt to replicate their advances and avoid their mistakes.

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Part of what makes ProjectSauron so impressive is its ability to collect data from computers considered so sensitive by their operators that they have no Internet connection. To do this, the malware uses specially prepared USB storage drives that have a virtual file system that isn’t viewable by the Windows operating system. To infected computers, the removable drives appear to be approved devices, but behind the scenes are several hundred megabytes reserved for storing data that is kept on the “air-gapped” machines. The arrangement works even against computers in which data-loss prevention software blocks the use of unknown USB drives.

Kaspersky researchers still aren’t sure precisely how the USB-enabled exfiltration works. The presence of the invisible storage area doesn’t in itself allow attackers to seize control of air-gapped computers. The researchers suspect the capability is used only in rare cases and requires use of a zero-day exploit that has yet to be discovered. In all, Project Sauron is made up of at least 50 modules that can be mixed and matched to suit the objectives of each individual infection.

“Once installed, the main Project Sauron modules start working as ‘sleeper cells,’ displaying no activity of their own and waiting for ‘wake-up’ commands in the incoming network traffic,” Kaspersky researchers wrote in a separate blog post. “This method of operation ensures Project Sauron’s extended persistence on the servers of targeted organizations.”