[b]Their Common First[/b]:Viruses, worms, Trojans, and bots are all part of a class of software called malware. Malware is a short for malicious software. It is code or software that is specifically designed to damage, disrupt, steal, or in general inflict some other “bad” or illegitimate action on data, hosts, or networks. By the way Malware cannot damage physically your hardware they just damage your data and software that is infected. 1. Virus can transfer from file to file, worms transfer from system to system, while Trojan cannot spread by its own. In other words virus needs a file to be infected and send to other system ,for a Trojan horse to spread, you must invite these programs onto your computers; for example, by opening an email attachment or downloading and running a file from the Internet, while worms transfer to system to system. 2.A computer virus is a type of malware that propagates by inserting a copy of itself into and becoming part of another program. It spreads from one computer to another, leaving infections as it travels. Viruses can range in severity from causing mildly annoying effects to damaging data or software and causing denial-of-service (DoS) conditions. Almost all viruses are attached to an executable file, which means the virus may exist on a system but will not be active or able to spread until a user runs or opens the malicious host file or program. Trojan files claim to be something desirable but, in fact, are malicious,Trojan horses contain malicious code that [b]when triggered[/b] cause loss, or even theft, of data A Trojan Horse is a destructive program that "working" as a benign application ( (like changing your desktop, adding silly active desktop icons) or can cause serious damage by deleting files and destroying information on your system. Trojans are also known to create a back door on your computer that gives malicious users access to your system, possibly allowing confidential or personal information to be compromised,.Worms is similar to virus but its spread rather than your computer sending out a single worm or sending out hundreds or thousands of copies of itself, creating a huge devastating effect in your computer. Short Explanation: Virus and worms are the same but not the same in the way they spread while Trojan's cant spread by its own. Hope you understand now their difference.

Last edited by networkmancer (2008-05-12 00:40:59)