The Virtumonde strain and its variants have been on the web for a few years now. This program shows it's self in many different ways and is know by winfixer, WinAntiVirus Pro, WinAntiVirus Pro and Vundo.
The tell tail signs of being infected with this are tons of pop-ups, home page highjacked and false anti-virus warnings. This program actually tracks all your online browsing and then targets ads to the sites you have visited. It will also go out and download fake anti-virus programs and then runs scans on your computer. You should never purchase anything that this program is trying to sell you as it is a gimmick and will do you no good.
Some other ways to tell you have Vundo specifically is if you have any of the following files installed on your computer.
C:WINDOWSsystem32vturr.dll
C:WINDOWSsystem32fcissfvg.dll
C:WINDOWSsystem32lyssmlnb.dll
C:WINDOWSsystem32yjsallam.dll
There are many other files but if you have any of the above then you have the vundo strain.
The two most common causes for infection is installing a browser plug-in or codec. This happens when you try to listen to a file or watch a file online and they tell you, you need to install some piece of software to watch it or listen to it. Trusted sites like cnn and fox it's ok to install such things but if you have never heard of the site before then you should not install whatever it is asking you to.
Another way people have gotten infected is from having the old Java program installed. This program had a few flaws that were being exploited and if you never update that program you left yourself unwittingly open to infection.
Those who are infected with this strain may find that their current anti-virus software and anti-spyware software find the virus but can not remove it. When this is the case you will need to use specific tools to remove this threat or purchase better anti-virus and anti-spyware software.
Even with all the right tools to get the job done many people who are computer illiterate may not want to try and remove this them selves as it can take a few hours and you need step by step guides for doing it. If that is you then consider hiring a pro to remove the trace from your computer. The cost will vary widely but if you call around you might be able to find someone for hundred or so bucks.
