Payload

Payload is a term used in computing to describe the piece of data that is transmitted over a given network. The payload is usually the meaningful part of the data transmission and is the part which is intended for the recipient. It is distinct from the transmission overhead which includes the packet header and other framing information.

In the context of computer security, the payload is the part of a program or attack that is malicious or otherwise generates a response from the target system. This response can be in the form of physical damage, data destruction, or installation of malicious code. Traditional computer viruses commonly include a payload, but newer breeds of malware such as ransomware can also contain payloads.

The source of the payload must be taken into account when analyzing malicious code. Exploits often include a payload which renders the code functional on a vulnerable system and allows the software to do what it was designed to do. Payload-based malware can be difficult to detect because it often requires the malicious code to execute on the target system in order for it to be detected.

In network computing, the payload is the payload of the packet frame for the protocol. In terms of protocols, the data payload is the part of the data stream which is part of an application protocol, such as HTTP. The payload, as distinct from network routing information, can be carried through multiple networks before being delivered. For example, in Internet Protocols the payload is part of the IP datagram and is the data application layer, such as protocol messages, data, and code, that is sent out of the network interface card for transmission over the underlying physical layer.

Payload is an important concept in the security of networks and systems as malicious payloads can alter the function of systems, allowing for the execution of malicious code, data theft and destruction, and the compromise of networks.