Malware used to send large amounts of garbage data (a “flood”) to the target, disrupting their communications. Flooders are typically deployed over network channels such as IRC, but specialized flooder versions for email, SMS, and instant messaging services also exist.
Flooders should not be confused with network flooding attacks (also known as denial-of-service attacks, or DOS.) Flooders aim to disrupt user communications as an act of cyber vandalism or as a diversionary measure. By contrast, network flooding attacks aim to overwhelm the system with repeat requests and crash it.