Security researchers have revealed a new attack to steal passwords, encryption keys and other sensitive information stored on most modern computers, even those with full disk encryption.
The attack is a new variation of a traditional Cold Boot Attack, which is around since 2008 and lets attackers steal information that briefly remains in the memory (RAM) after the computer is shut down.
However, to make the cold boot attacks less effective, most modern computers come bundled with a safeguard, created by the Trusted Computing Group (TCG), that overwrites the contents of the RAM when the power on the device is restored, preventing the data from being read.
Now, researchers from Finnish cyber-security firm F-Secure figured out a new way to disable this overwrite security measure by physically manipulating the computer's firmware, potentially allowing attackers to recover sensitive data stored on the computer after a cold reboot in a matter of few minutes.
"Cold boot attacks are a known method of obtaining encryption keys from devices. But the reality is that attackers can get their hands on all kinds of information using these attacks. Passwords, credentials to corporate networks, and any data stored on the machine are at risk," the security firm warns in a blog post published today.
Like the traditional cold boot attack, the new attack also requires physical access to the target device as well as right tools to recover remaining data in the computer's memory.
"It's not exactly easy to do, but it is not a hard enough issue to find and exploit for us to ignore the probability that some attackers have already figured this out," says F-Secure principal security consultant Olle Segerdahl, one the two researchers.
"It's not exactly the kind of thing that attackers looking for easy targets will use. But it is the kind of thing that attackers looking for bigger phish, like a bank or large enterprise, will know how to use."