I understand that CPU silicon (for example) is scrutinized for backdoors but there are other aspects of a computer system that may "leak data" to the outside world unbeknownst to the owner regardless of driver or OS configuration.
I'm looking for advice on how to protect myself from hardware-based exploits such as CPU-silicon backdoors, Bluetooth or wifi hardware-based vulnerabilities, or even hacks in BIOS of the motherboard or any connected devices.
Some examples of a hardware hack could include
- Setting a jumper pin to enable discreet functionality
- A undocumented keyboard sequence (other than control-alt-delete) that bypasses a BIOS password
A bluetooth receiver that "wakes up" when a magic packet is seen
An integrated camera and microphone that records data to NVRAM when conditions apply
A GPS receiver that wakes up when at a certain location.
What guidelines should I follow to purchase hardware (computers, networking equipment, power supplies, etc) that is secure at a hardware & firmware perspective? (before the OS level)
The answers I'm looking for could be either legal/contractual, or technical in nature.