2018/02/07 by Mordechai Guri, Andrey Daidakulov, Guri, Mordechai +3
Computer Science · #Internet Traffic Analysis and Secure E-voting #Cryptographic Implementations and Security #Advanced Malware Detection Techniques
paper · pdf · doi:10.48550/arxiv.1802.02317
In this paper, we show that attackers can leak data from isolated, air-gapped\ncomputers to nearby smartphones via covert magnetic signals. The proposed\ncovert channel works even if a smartphone is kept inside a Faraday shielding\ncase, which aims to block any type of inbound and outbound wireless\ncommunication (Wi-Fi, cellular, Bluetooth, etc.). The channel also works if the\nsmartphone is set in airplane mode in order to block any communication with the\ndevice. We implement a malware that controls the magnetic fields emanating from\nthe computer by regulating workloads on the CPU cores. Sensitive data such as\nencryption keys, passwords, or keylogging data is encoded and transmitted over\nthe magnetic signals. A smartphone located near the computer receives the\ncovert signals with its magnetic sensor. We present technical background, and\ndiscuss signal generation, data encoding, and signal reception. We show that\nthe proposed covert channel works from a user-level process, without requiring\nspecial privileges, and can successfully operate from within an isolated\nvirtual machine (VM).\n