Trojan horses usually use social engineering, like a pirated software or a fake Office document send by mail, to gain control over a computer. Once installed, they usually hide themselves from the system and make it impossible for the user to remove.
This is a general explanation about different kind of online threats. What they do, and how. Introduction to viruses, malware, worms, adware and others.
Got infected with Gootkit malware? Follow this step by step guide to get rid of it. Our guide also includes a short analysis of the malware.