I was doing some testing on my Windows XP system surfing about some
sites of “ill repute” with IE6 and got hit with something called Spy
Sheriff.

Spy Sheriff is like a watered down version of PS Guard or Smithfaud.  Like PS
Guard, Spy Sheriff claims to want to remove all the malware it infects
you system with.  Both of these horrible bits of malicious code
are what I like to call scareware.  The get loaded on to your
system along with about 100 other viruses, worms and trojans and take
over you desktop with a message like “Spyware Infection”.  The
application then “scans” your system.  And tells you that you must
activate the Spy Sheriff or PS Guard in order to clean your
system.  When attempt to remove Spy Sheriff using Add/Remove programs, it simply adds itself again once you reboot.

In the background, all the malware they loaded on your system are
collecting data and send status report to a parts of the world. 
The scareware will usually make sure you know this to convince you to
buy their product.  DO NOT GIVE THEM YOUR CREDIT CARD INFO!

Here is how to remove Spy Sheriff.