What is an Air-gapped computer?
An air-gapped computer is a computer that is used to safeguard critical data and protect it from hackers and malware. It is a computer system that is not connected to any other computer. It is never online as it has no Internet connection to remove the possibility of it ever getting hacked or infected. In air-gapped computers, the objective is to keep custom apps (programs) and data safe. Since there is a possibility of malware propagating through Flash drives, they too are used sparingly. Any type of connection to all types of removable drives is avoided as far as possible. Air gapped computers are used to store data critical to business houses, military, and similar entities. You might have seen in movies that such air-gapped computers (or maybe museum artifacts) are protected by military-grade laser sensors so that an alarm is sounded when any unauthorized person gets closer to the computer. Normally, air-gapped computers are stored in separate rooms, equipped with high security. It is called air-gapped because the only thing between the computer and other items around it is air.
Is an air-gapped computer unhackable?
Well, almost. The purpose of air-gapped computers is to create an environment where data or programs cannot be stolen or infected by malware. But methods exist to break into such computers: Social Engineering is where a person with authority to the air-gapped computer is submitted into giving the secrets. Or, to infect the computer by injecting some type of malware. From a short distance, data on a computer can be copied by modulating it over the sound. In this case, too, it would be a deliberate attempt to harm the organization whose system is being targeted. The speaker and mic would take commands and process them in an inaudible range of sound, once a malware to that effect is injected into the system. Inaudible commands received by the mic are processed inaudibly by speakers of the computers. Data can be stolen using such sound waves. In both cases, the physical presence of the hacker or a person planted/compromised by him should have access to the air-gapped computer. This requirement of physical presence removes the possibility of a remote attack (except data over sound). Thus, though breakable, air-gapped computers are extremely secure.
How to create an air-gapped computer?
Creating an air-gapped computer is easy. Just disconnect the LAN (Ethernet) cable, disable Wi-Fi card, and Bluetooth on the computer. Perform a clean format on the computer. Install only the required program/app and data on this computer. In the future, if the need arises to transfer data to this computer or from this computer, use clean flash drives. Always keep the antimalware software updated on this computer. Use a Flash drive to update virus definitions instead of connecting the air-gapped computers to the Internet for the purpose. Connecting such computers to a WAN or Internet for even a few minutes may defeat the purpose of air-gapping of those computers. The above explains air-gapped computers’ meaning and whether they can be broken into.
