How do i remove an HTTP Malicious Toolkit Variant?

Occasionally upon startup of IE my NIS2009 reports an attempt by my machine, to contact:

 

           jl.chura.pl/rc/

    IP:  218.93.205.30

 

was blocked because the network traffic matches the signature of a known attack.

This is obviously some code that has been injected into my instance of IE, but full system scans and scans of the specific folder do not identify any threats. How could I remove this problem?