Dropper

A dropper is a unique member of the malicious Trojan family, typically a standalone application that deposits other standalone applications into an operating system. Infections may include different Trojans, worms and backdoors. In most cases, a dropper comes with a number of infections packed within its frame. Once it has been executed, all internal files and applications are extracted and executed simultaneously. The dropper often masks itself as an innocent or multimedia file to conceal malicious intent. Trojan writers use special utilities called joiners to create them. They permit a writer to customize functions of the Trojan and store a large number of files into its packaging. The dropper has the ability to unload components right into the memory of an operating system, making detection of the entire process very difficult for anti-virus software. This Trojan is often used to distribute adware and spyware to a user’s system. The most common form of this infection has these aliases: Small, ZomJoiner, ExeBundle and ExeStealth.