Security researchers have identified a new suspicious program that is copying itself to PCs via USB mass storage devices. The program, known as Stuxnet, looks like a somewhat standard-issue piece of malware, with a couple of key exceptions. The two drivers associated with the Trojan are digitally signed with the certificate of Realtek Semiconductor, a major manufacturer of computer products based in Taiwan. The Trojan was discovered in mid-June by an antimalware company in Belarus called VirusBlokAda.
Source: https://threatpost.com/possible-new-rootkit-has-drivers-signed-realtek-071510/74217/