RF signal exfiltration is a spying technique whereby RF signals are used to transmit sensitive or secret information out of a secure facility (such as an embassy).
Attackers do not need physical access to the target system and can operate from a distance. They can manipulate transmitted signals in various ways, such as changing signal strength, frequency, or modulation, to trick the receiver into accepting the fake signal as legitimate. This can allow the attacker to inject false data into the system, disrupt communications, or gain unauthorized access to the network.
Technical surveillance countermeasures are vital, particularly for sensitive environments such as embassies.