Can you differential rouge antivirus and legitimate antivirus?

Can you differential between rouge antivirus and legitimate antivirus? Some of you may do differential, and most you will have not idea how to differential between it...

With the sophisticated skills that 'bad' guys had, lots of fake window dialog are display and attempting to entice users click on their dialog. When 'Ok' or 'Cancel' or 'Close' dialog button were clicked, this will redirect users to malicious site, which will install the program. Some website will download the program automatically (drive-by installation) on users systems !

Tips:
1. Before install any new antivirus on your systems, please refer to "http://www.virustotal.com/sobre.html". Most of the legitimate antivirus will be listed and used to scan malicious file. If your program is not belong to the list. BE AWARE and 'SHIFT + DEL' when necessary.

Other than VirusTotal that provide similar functionality, refer to http://www.web2secure.com/2008/09/free-online-multiple-av-scan.html

2. Once you noticed that your system getting slow, unstable, computer security settings changed after installed unknown antivirus program. QUICKLY uninstall the unknown antivirus program. Install any legitimate trial version of antivirus or free version of antivirus may help you temporarily clean your systems from any malicious file.



PS: I not get any benefit from VirusTotal, and VirusTotal just one of my personal favourite website. :D