Hackers can tap USB devices in new attacks, researcher warns
Karsten Nohl to describe attack method at Black Hat hacking conference in Las Vegas next week
USB devices such as mice, keyboards and thumb-drives can be used to hack into personal computers Reuters reported citing a top computer researcher.
Karsten Nohl, chief scientist with Berlin's SR said that the potential new class of attacks evade all known security problems as hackers could load malicious software onto tiny, low-cost computer chips that control functions of USB devices but which have no built-in shields against tampering with their code.
"You cannot tell where the virus came from. It is almost like a magic trick," said Nohl, whose research firm is known for uncovering major flaws in mobile phone technology.
According to Reuters, the finding shows that bugs in software used to run tiny electronics components that are invisible to the average computer user can be extremely dangerous when hackers figure out how to exploit them. Security researchers have increasingly turned their attention to uncovering such flaws.
Nohl said his firm has performed attacks, which he will describe at next week's Black Hat hacking conference in Las Vegas, by writing malicious code onto USB control chips used in thumb drives and smartphones. Once the USB device is attached to a computer, the malicious software can log keystrokes, spy on communications and destroy data, he said.
Computers do not detect the infections when tainted devices are inserted into a PC because anti-virus programs are only designed to scan for software written onto memory and do not scan the "firmware" that controls the functioning of those devices, he said.
Nohl said he would not be surprised if intelligence agencies like the National Security Agency have already figured out how to launch attacks using this technique.
SR Labs tested the technique by infecting controller chips made by major manufacturer Taiwan's Phison Electronics Corp, and placing them into USB memory drives and smartphones running Google Inc's Android operating system.
Nohl said he believes hackers would have a "high chance" of corrupting other kinds of controller chips besides those made by Phison, because their manufacturers are not required to secure software. He said those chips, once infected, could be used to infect mice, keyboards and other devices that connect via USB.
"The sky is the limit. You can do anything at all," he said.
In his tests, Nohl said he was also able to gain remote access to a computer by having the USB instruct the computer to download a malicious program with instructions that the PC believed were coming from a keyboard. He said he was also able to change what are known as DNS network settings on a computer, essentially instructing the machine to route Internet traffic through malicious servers.
Once a computer is infected, it could be programmed to infect all USB devices that are subsequently attached to that PC, which would then corrupt machines that they contact.
"Now all of your USB devices are infected. It becomes self-propagating and extremely persistent," Nohl said. "You can never remove it."