Trojan Viruses can be a royal pain in the @$$. This virus installs malicious software while under the guise of doing something else. Trojan horses are more notorious for installing backdoor programs which allow unauthorized remote access to the victim's machine by unwanted parties - normally with malicious intentions.
WebSense Security Labs has issued a new Trojan virus alert on August 14th. There is a new Storm Trojan Tactics being used within emails. The new emais are using the Subject: "Greeting Card your-name" and containing the following in the email body.
{xtypo_quote}Class-mate(some name) has created Greeting Card for you your-name at christianet.com. To see custom Greeting Card, simply click on the following link: http://some-url.
Send a FREE gretting card from christianet.com whenever you want by visiting us at: http://some-url. This service is provided and hosted by christianet.com.{/xtypo_quote}
the URLs point to a compromised machine that is hosting the BOT and an HTTP proxy. The same exploit code attempts to run the file without user intervention; however, the file name has changed to msdataaccess.exe.
There is a nice article about removing the Trojan Virus from your computer.