MSN Block Checker

You may have heard about MSN Block Checker. If you haven’t, it’s a small program to see who’s blocking you on MSN. Sounds good, huh?

However, it’s not so good. First, all it does is to tell you whether a given msn contact is online or not. Second, it ignores Windows Messenger completely and shows anyone using this version as offline. Third, and on top of everything, it infects your computer with an evil little virus called Adclicker-DF which gives you lots of spyware and modifies the Windows registry.

The virus is a Trojan Horse and reveals itself as "System Process" in the "Add or Remove Programs" tab in the control panel, as well as places two files called navshext.dll and ccapp.exe in the "X:\WINDOWS\system32" folder. These files imitate legitimate anti-virus files and are fake. Both navshext.dll and ccapp.exe are normally used by Symantec (Norton Anti-Virus).

If being uninstalled, MSN Block Checker will try going online, so make sure you’re disconnected from the Internet. Preferably, uninstall in Safe Mode (press F8 during startup). If necessary, delete the files manually, as they appear to be the actual virus.

However, consider that by uninstalling, the computer may crash – in worst case every time you start it.

More info here.