A beacon is a type of network traffic that is sent from a compromised device to a command and control (C2) server, which is a remote system that controls the malicious activities of the device . A beacon is used to establish and maintain communication between the device and the C2 server, as well as to receive instructions or exfiltrate data .

A common characteristic of a beacon is that it is periodic, meaning that it is sent at regular intervals, such as every few minutes or hours . This helps the C2 server to monitor the status and availability of the device, as well as to avoid detection by network security tools .

Another common characteristic of a beacon is that it is small and identically sized, meaning that it contains minimal or fixed amount of data, such as a simple acknowledgment or a random string . This helps the device to conserve bandwidth and resources, as well as to avoid detection by network security tools .