Watch out for the virtumonde trojan that’s kicking about this festive season.
This infects using holes in Sun Java and gets into Windows registry and System 32 files. If you notice a randomly generated dll file name it’s worth checking.
Common symptoms are pop up windows usually saying that you need to download software to fix the problem! Don’t click on these popups!
This can be a sticky problem to remove as the infected dll’s start when you boot up your machine.
Best solution if you’re not sure, aside from checking your security settings, is to run Spybot to see if anything turns up, but this doesn’t always remove the problem permanently. You should also try ATF cleaner to remove all temporary files on your computer and then run Malwarebyte’s Anti-Malware. If any problems come up ensure that you check them all and ‘remove selected’.
On restart the system may be slower initially but this will recover. You should then run HiJackThis to generate a log file and submit this along with the Anti-Malware report to an appropriate forum, such as Safer Networking.
You will get the best and most thorough advice from the experienced teams on these forums.