The US Patent and Trademark Office has granted Kaspersky Labs a patent for a hardware-based antivirus. The Moscow-based security company is behind one of the most popular paid antivirus applications, and offers a range software security options.

Filed last September, the firm's freshly minted patent (7,657,941) is for an antivirus system "based on a hardware-implemented AV module for curing infected computer systems and a method for updating AV databases for effective curing of the computer system." The device is installed between a computer's disk drive and CPU/RAM, and is connected to the system bus or integrated into the disk controller. Once in place, it determines what data will be permitted to write to the disk and issues threat alerts.

The dongle is basically a separate system running an embedded antivirus program. It has its own processor and memory, and it can work alone or with AV software installed on the primary computer. Such a solution offers several benefits. For starters, it's situated below the level of rootkits and thus cannot be bypassed by them. Also, since the device carries its own CPU and RAM, it would require few to no resources from the main computer to operate.

Whether Kaspersky's hardware-based AV is more effective remains to be seen, but some are already criticizing it. It's said the device doesn't have network access, so it can't update on its own and will require the assistance of software installed on your machine, introducing another possible security risk.