Air-gapped computers are considered to be high-value, and thus, interesting targets for hacking. Even though they may not have a network connection, there are ways a hacker could potentially steal data from them. Here are the top four methods, each representing a cybersecurity risk:
This is the earliest attack vector. Ranging from USB port and cable leakage, and all the way to eavesdropping on the EM radiation from the memory bus, this method was the first to be widely explored, which has led to EM shielding becoming a popular anti-measure.
This method goes far beyond speakers, as even disk drive noise can be used. A hacker can use a simple smartphone to decipher the kind of audio signals that the human ear cannot differentiate from background hum.
It’s possible to perform a thermal hack to measure bandwidth in a couple of tens of bits per second over a short distance. The weakness of this method is that it’s not possible to execute it in a covert way, so it can hardly be a cybersecurity threat in most environments.
With this method, it’s possible to reach a transfer rate of 4 kbps. By hacking the security cameras and accessing their feed, it’s possible to observe the system’s LEDs, if it has them. They can leak data, and a significant amount of it. If the flickering frequency is above 60Hz, the human eye has a hard time detecting it, but a device is perfectly capable of reading these signals.