What is a Trojan Horse?
Trojan horses are impostors—files that claim to be something desirable but, in fact, are malicious. A very important distinction between Trojan horse programs and true viruses is that they do not replicate themselves. Trojan horses contain malicious code that when triggered cause loss, or even theft, of data. 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. Trojan.Vundo is a Trojan horse. What is a worm? Worms are programs that replicate themselves from system to system without the use of a host file. This is in contrast to viruses, which requires the spreading of an infected host file. Although worms generally exist inside of other files, often Word or Excel documents, there is a difference between how worms and viruses use the host file. Usually the worm will release a document that already has the “worm” macro inside the document. The entire document will
Virus has become a generic term for any malicious code. There is a kind of malicious code called a Trojan Horse. You may guess from the name that it is an application that appears benign, but contains a malicious payload. One, of many, possible scenario is that someone using that computer downloaded some application which appeared to be benign, but was from an untrustworthy source, acted as Trojan Horse which contained BO2K as it’s payload. Thus running this seemingly benign software would result in the payload being delivered without the users knowledge. This is why it’s extremely important to be careful about running applications downloaded from anywhere. Running a virus scanner at all times that checks files as they are downloaded or viewed from a remote site is a really good idea if one is downloading any kind of applications. Many of these scanners watch not only files already on the hard drive but also check files as they are downloaded, attached to e-mail and even executable cod
