New hack can steal crypto private key from air-gapped wallet

A new security threat has come to light, that targets a non-networked wallet…

by Tom Rodgers

A cybersecurity researcher from Ben-Gurion University of the Negev in Israel has demonstrated a new hack that can clean out a bitcoin wallet from an air-gapped computer.

In a YouTube video explaining the hack, Dr Mordechai Guri shows how it is possible to leak a Bitcoin private key despite the fact that the computer hosting the wallet is not networked, uses no Bluetooth nor WiFi and is not connected to the internet.

Specially developed malware known as ‘bridgeware’ leaks the bitcoin private key across the air gap where it is picked up by a smartphone, using ultrasonic signals undetectable to the human ear.

The hack takes less than three seconds in the demonstration video.

In a second video Dr Guri manages to steal a private key from a Raspberry Pi, a stripped back micro-PC with no WiFi, Bluetooth, network, internet connection, nor a keyboard or screen.

This time, the bridgeware leaks the private key from the Raspberry Pi to a nearby smartphone over air-gap using electromagnetic signals. This time, the hack takes a little longer but is still completed in under 20 seconds.

Dr Guri and his research team had previously shown how it was possible to steal data from air-gapped, speakerless computers by using ‘DiskFiltration’.

The slightly terrifying method remotely controls the movements of hard disk drives’ actuator arms to generate sounds at specific audio frequencies. Data is then picked up by a nearby receiver like a microphone or smartphone.

Dr Guri wrote: “With DiskFiltration we were able to covertly transmit data (for example passwords, encryption keys, and keylogging data) between air-gapped computers to a nearby receiver at an effective rate of 180 bits per minute”.

This news should spark already nervous wallet holders to up their security even further. Either that, or treat every nearby smartphone as a potential cryptocurrency thief….