{"id":34782,"date":"2020-05-04T16:06:00","date_gmt":"2020-05-04T16:06:00","guid":{"rendered":"http:\/\/d021c95a-207f-4916-9b70-47732eca2cc1"},"modified":"2020-05-04T16:06:00","modified_gmt":"2020-05-04T16:06:00","slug":"academics-turn-pc-power-units-into-speakers-to-leak-secrets-from-air-gapped-systems","status":"publish","type":"post","link":"https:\/\/www.threatshub.org\/blog\/academics-turn-pc-power-units-into-speakers-to-leak-secrets-from-air-gapped-systems\/","title":{"rendered":"Academics turn PC power units into speakers to leak secrets from air-gapped systems"},"content":{"rendered":"

\"computer<\/span>Image: IgorShubin<\/span> <\/p>\n

Academics from an Israeli university have published new research last week showing how an attacker could turn a computer’s power supply unit into a rudimentary speaker that can secretly transmit data from an infected host using audio waves.<\/p>\n

The technique, named POWER-SUPPLaY, is the work of Mordechai Guri, the head of R&D at the Ben-Gurion University of the Negev, in Israel.<\/p>\n

Over the last half-decade, Guri has been pioneering research into new covert data exfiltration channels. The techniques Guri has been developing can be used for stealing data through unconventional means.<\/p>\n

Guri has been developing these techniques specifically for extracting data from air-gapped systems — computers isolated on local networks with no internet access.<\/p>\n

Such computers are often used on government or corporate networks to store sensitive data, such as classified files or intellectual property.<\/p>\n

Air-gapped systems are protected by several layers of defenses, on top of the “air gap,” and you need novel data transmission techniques to go around these defenses.<\/p>\n

For example, some air-gapped systems don’t have speakers, because it’s been proven in the past that speakers could be abused to leak information from a secure system using inaudible sound waves.<\/p>\n

Meet POWER-SUPPLaY, a new data exfiltration technique<\/h3>\n
\n<\/section>\n

In a research paper shared with ZDNet yesterday, Guri said the POWER-SUPPLaY technique was developed for these types of situations, where speakers have been removed from air-gapped systems.<\/p>\n

By using specially-crafted malware, the Israeli researcher says that a power supply unit (PSU) can be transformed into a very simple speaker capable of emitting the most basic of audio waves.<\/p>\n

[Guri has only developed and studied the data exfiltration technique. Guri’s work does not focus on planting the malware on air-gapped systems or getting near to an air-gapped system to steal data. This is out of scope of his project.]<\/em><\/p>\n

Guri says the trick behind the POWER-SUPPLaY technique is to manipulate power inside a PSU’s capacitors to trigger a “singing capacitor phenomenon.”<\/p>\n

This phenomenon generates acoustic waves when current passes through a capacitor at various frequencies. By controlling the power frequencies, the POWER-SUPPLaY malicious code can also control the audio waves, and hence, hide data inside it.<\/p>\n

\"singing-capacitor.png\"<\/span>

\"singing-capacitor.png\"<\/span><\/p>\n

<\/noscript> Image: Mordecai Guri<\/span><\/p>\n

“Our technique works with various types of systems: PC workstations and servers, as well as embedded systems and IoT devices that have no audio hardware.<\/p>\n

“Binary data can be modulated and transmitted out via the acoustic signals. The acoustic signals can then be intercepted by a nearby receiver (e.g., a smartphone), which demodulates and decodes the data and sends it to the attacker via the Internet,” Guri added.<\/p>\n

\n