A type of Trojan that is usually smuggled into a PC via an email or attachments or download, and launches malware by “dropping” it. Droppers often go undetected because they are hidden, not being associated with files like much other malware. They impede the functioning of targeted computers, and can install themselves onto a disc or hard drive. They launch their payload whilst disguising themselves within computer systems. Generally the most effective protection against droppers is anti-spyware.