Wired had a good article explain a new class of hacks, Forget Software—Now Hackers Are Exploiting Physics "Both of those new attacks use a technique Google researchers first demonstrated last March called ‘Rowhammer.’ The trick works by running a program on the target computer, which repeatedly overwrites a certain row of transistors in its DRAM flash memory, ‘hammering’ it until a rare glitch occurs: Electric charge leaks from the hammered row of transistors into an adjacent row. The leaked charge then causes a certain bit in that adjacent row of the computer’s memory to flip from one to zero or vice versa. That bit flip gives you access to a privileged level of the computer’s operating system. It’s messy. And mind-bending. And it works."
Rowhammer is far from the only new hacking technique that exploits computers’ physical properties. Proof-of-concept malware shown off by Israeli researchers over the summer, for instance, uses the sound of computers’ cooling fans or hard drive motors to transmit stolen data as audio. Another group of Israelis showed last year they could use just $300 of handheld equipment to extract encryption keys from a computer by monitoring the radio emissions leaked by its processor’s power use.