I heard from a reader recently whose PC was infected with the IRP Hook rootkit. The AVG anti-virus software installed on his PC detects the infection, but will not clear it off. Nor will Spybot or Ad-aware.
The infection is causing his PC to slow down, taking forever to startup and shutdown and load web pages.
The problem with this infection is that it is buried so deep inside Windows that it is very difficult for AVG to remove it. Instead, you need to use a combination of three tools, run in the right order to remove it. To do so:
1. First download and run rkill, available here: http://www.bleepingcomputer.com/download/rkill/
2. Next, download and run TDSS Killer from Kaspersky Labs: http://support.kaspersky.com/faq/?qid=208280684
3. Finally run Malwarebytes Anti-malware, which you’ll find here: http://tiny.cc/fbojhw
Once you’ve finished running the tools, reboot your system and then rescan your system with your main anti-virus software. Hopefully nothing will be found!