Just like the original Trojan Horse that was built by the Greeks, the Trojan Horse Virus for your computer is actually something that is evil and bad concealed within something that seems good and positive. For anyone that might not know, a quick history lesson, the original Trojan Horse was given as a gift to the City of Troy by the Greeks who were losing the war but within this large wooden horse that was rolled into the gates of Troy was the Greek Army that came out at night when no one was looking and destroyed the city.

The computer virus variety of the Trojan Horse was first discovered in 2002 within sendmail and OpenSSH packages both included the Trojan Horse. It was done by a hijacker that broke into the distribution sites and replaced the software with his own damaged and infected ones. That is one way that your system can be given a Trojan, through software downloads and installation.

However, the most common way that users are infected with a Trojan program is through the spreading of it through emails. The sender will send it to the recipient within an email attachment that might say something like