This papers shows that attackers can leak data from isolated, air-gapped computers to nearby smartphones via covert magnetic signals. The proposed covert channel works even if a smartphone is kept inside a Faraday shielding case, which aims to block any type of inbound and outbound wireless communication (Wi-Fi, cellular, Bluetooth, etc.). Malware is implemented to control the magnetic fields emanating from the computer by regulating workloads on the CPU cores. Sensitive data such as encryption keys, passwords, or keylogging data is encoded and transmitted over the magnetic signals. A smartphone located near the computer receives the covert signals with its magnetic sensor. I present technical background, discuss signal generation, data encoding, and signal reception. The proposed covert channel works from a user-level process, without requiring special privileges, and can successfully operate from within an isolated virtual machine (VM).

中文翻译：

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MAGNETO：通过 CPU 生成的磁场在气隙系统和附近智能手机之间建立隐蔽通道

本文表明，攻击者可以通过隐蔽的磁信号将数据从隔离的气隙计算机泄露到附近的智能手机。即使智能手机放在法拉第屏蔽盒内，所提出的隐蔽通道也能发挥作用，法拉第屏蔽盒旨在阻止任何类型的入站和出站无线通信（Wi-Fi、蜂窝网络、蓝牙等）。恶意软件通过调节 CPU 内核的工作负载来控制计算机发出的磁场。加密密钥、密码或键盘记录数据等敏感数据通过磁信号进行编码和传输。位于计算机附近的智能手机通过其磁传感器接收隐藏信号。我介绍技术背景，讨论信号生成、数据编码和信号接收。所提出的隐蔽通道在用户级进程中工作，无需特殊权限，并且可以在隔离的虚拟机 (VM) 内成功运行。