>'Not being able to get a hold of your secrets' is a much better line of defense than 'I think I can make it hard for something to exfiltrate my secrets that th

>'Not being able to get a hold of your secrets' is a much better line of defense than 'I think I can make it hard for something to exfiltrate my secrets that they've pilfered'. Especially since the latter is probably not really true. reminds me of this: > Air-gapped networks are isolated, separated both logically and physically from public networks. Although the feasibility of invading such systems has been demonstrated in recent years, exfiltration of data from air-gapped networks is still a challenging task. In this paper we present GSMem, a malware that can exfiltrate data through an air-gap over cellular frequencies. Rogue software on an infected target computer modulates and transmits electromagnetic signals at cellular frequencies by invoking specific memory-related instructions and utilizing the multi-channel memory architecture to amplify the transmission. Furthermore, we show that the transmitted signals can be received and demodulated by a rootkit placed in the baseband firmware of a nearby cellular phone. We present crucial design issues such as signal generation and reception, data modulation, and transmission detection. We implement a prototype of GSMem consisting of a transmitter and a receiver and evaluate its performance and limitations. Our current results demonstrate its efficacy and feasibility, achieving an effective transmission distance of 1 - 5.5 meters with a standard mobile phone. When using a dedicated, yet affordable hardware receiver, the effective distance reached over 30 meters. https://www.usenix.org/system/files/conference/usenixsecurity15/sec15-paper-guri-update.pdf https://www.usenix.org/system/files/conference/usenixsecurit...