I've heard of this one going around. I'd also like to warn people of one called Antivirus Soft. It somehow managed to get into my computer and randomly popped up out of nowhere. I blocks everything (Even CTRL + ALT + DELETE) except the page to its site for you to buy the supposed "program." It's pretty nasty.
If you have an XP and get hit by it, the best thing to do is restart your comp and upon loading, CTRL + ALT + DELETE before it loads and stop an .exe that looks like xceed.exe or something of the likes. It looks pretty suspicious either way.
Then watch and do
this.