AntiSpy

Win32/FakeRean is one of those fake antivirus programs that claim to detect all sorts of viruses on your computer and urges you to purchase the full version. Obviously, the "viruses" that are detected are all fake and don't exist in your computer.

NOTE: A lot of removal guides found on the Internet did not mention that you need to repair Windows Update after you got infected by this. If you don't repair it, you won't be able to install system updates later on.

Also, Windows Defender gets wiped out after being infected.

Ridiculous naming convention from http://www.microsoft.com/security/portal/Threat/Encyclopedia/Entry.aspx?Name=Win32%2fFakeRean :

Win 7 Internet Security 2011
Vista Internet Security 2011
XP Internet Security 2011
Win 7 Internet Security
Vista Internet Security
XP Internet Security

Win 7 Antivirus Pro 2011
Vista Antivirus Pro 2011
XP Antivirus Pro 2011
Win 7 Antivirus Pro
Vista Antivirus Pro
XP Antivirus Pro

Win 7 Antivirus 2011
Vista Antivirus 2011
XP Antivirus 2011
Win 7 Antivirus
Vista Antivirus
XP Antivirus

Win 7 Antispyware 2011
Vista Antispyware 2011
XP Antispyware 2011

Win 7 AntiMalware 2011
Vista AntiMalware 2011
XP AntiMalware 2011
Win 7 AntiMalware
Vista AntiMalware
XP AntiMalware

Antivirus Win 7
Antivirus Vista
Antivirus XP

Antispyware Win 7
Antispyware Vista
Antispyware XP

Win 7 Defender 2011
Vista Defender 2011
XP Defender 2011
Win 7 Defender
Vista Defender
XP Defender
Win 7 Defender Pro
Vista Defender Pro
XP Defender Pro

Win 7 Guardian 2011
Vista Guardian 2011
XP Guardian 2011
Win 7 Guardian
Vista Guardian
XP Guardian

Antivirus Win 7 2011
Antivirus Vista 2011
Antivirus XP 2011

Win 7 Smart Security 2011
Vista Smart Security 2011
XP Smart Security 2011
Win 7 Smart Security
Vista Smart Security
XP Smart Security

Win 7 Security Tool 2011
Vista Security Tool 2011
XP Security Tool 2011
Win 7 Security Tool
Vista Security Tool
XP Security Tool

Total Win 7 Security
Total Vista Security
Total XP Security
Win 7 Security
Vista Security
XP Security