I downloaded Malwarebytes Anti-Malware today to take care of a pesky infection I got last night, It is a free download, but you can purchase the Pro version later for auto updates and such. It's the best one that I have used so far. I am usually pretty good at chasing them down and taking them out manually by just blocking a file or two and deleting a few registry entries but this one had so much going on it would have taken a week to get rid of. Most spyware programs that I had used in the past wouldn't take care of files loaded into memory so they would just come right back after reboot, but this one took care of that, and even a few more that I had blocked from running in the past few years that I had totally forgotten about.
This downloader installed on my computer and kept trying to install XP Antispyware 2009 and AntivirusPro, which is actually spyware/malware itself and then they try to get you to purchase it to get rid of everything that it just installed. You can do a restore but it won't get rid of the downloader. The bad thing of it is that the downloader that would keep popping up to tell you that your computer is infected totally disabled alot of my tools like Windows Defender, Vundofix, Combofix, HiJack This, Autoruns, and Spybot. It installed another file in the control panel to look like Security Center, but it was called Windows Security Center and would always turn off my firewall on startup.
I was also using SpywareBlaster which didn't recognize it ' Although that's the only one that I didn't have updated and also my Microsoft Windows Malicious Software Removal Tool wouldn't kill it from memory but all seems to be running good so far and I may upgrade to the Pro version of Malwarebytes unless stuff starts popping back up in a day or two.