An attacker spoofs a checksum message for the purpose of making a payload
						appear to have a valid corresponding checksum. Checksums are used to verify
						message integrity. They consist of some value based on the value of the
						message they are protecting. Hash codes are a common checksum mechanism.
						Both the sender and recipient are able to compute the checksum based on the
						contents of the message. If the message contents change between the sender
						and recipient, the sender and recipient will compute different checksum
						values. Since the sender's checksum value is transmitted with the message,
						the recipient would know that a modification occurred. In checksum spoofing
						an attacker modifies the message body and then modifies the corresponding
						checksum so that the recipient's checksum calculation will match the
						checksum (created by the attacker) in the message. This would prevent the
						recipient from realizing that a change occurred.