Funtenna can remotely steal data from air-gapped network using sound waves

A group of researchers has presented at the Black Hat conference Funtenna, a hacking technique to steal data from air-gapped network based on sound waves.

Imagine, If a remote hacker could steal classified information from a targeted computer without having to physically and Internet access to it.

A team of security researchers has demonstrated how to steal data from a computer by using sound waves. The researchers developed a new hacking technique called Funtenna which could be used by an attacker to exfiltrate data from a targeted computer even if it is in an Air-gapped network.

“Funtenna is a software-only technique which causes intentional compromising emanation in a wide spectrum of modern computing hardware for the purpose of covert, reliable data exfiltration through secured and air-gapped networks. We present a generalized Funtenna technique that reliably encodes and emanates arbitrary data across wide portions of the electromagnetic spectrum, ranging from the sub-acoustic to RF and beyond.

The Funtenna technique is hardware agnostic, can operate within nearly all modern computer systems and embedded devices, and is specifically intended to operate within hardware not designed to to act as RF transmitters.” states the description of the talk at the Black Hat conference.

The potential of this last discovery is enormous, as explained by the researcher Ang Cui of Red Balloon Security, the Funtenna radio signal hack could allow attackers to exploit Internet of Things devices to spy on any target. Gaming console, printer, washing machine and refrigerators could steal data from computers, even if they are isolated from the Internet.

The attackers have to install a malware on the target’s device such as a computer, a printer or an office phone. The malicious code is used by attackers to control the electronic circuit of the device (general-purpose input/output circuits), the data are sent out signals generated by vibrating them at specific frequencies.

The attacker then captures the signals generated by the vibrations by using an AM radio antenna, the Funtenna, that must be located at a short distance.

The Funtenna hacking technique is able to bypass any network security solution, the researchers also provided a Video PoC of an attack scenario.

“You have network detection, firewalls… but this transmits data in a way that none of those things are monitoring, this fundamentally challenges how certain we can be of our network security,” explained Cui.

 https://youtu.be/1H1Lv9DAJPg

The team of researchers will release a “proof-of-concept” code for other researchers.

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Pierluigi Paganini

(Security Affairs – Funtenna, hacking)