While drive-by downloads were noticed as early as 2007 they probably started before that. I know for a fact that they can happen even when visiting legitimate web sites. It happened to me twice in May 2010. They were both rogue Antivirus downloads. One was a suite of malware (several nasties), the other Antispyware Soft. Thanks to the information on this forum and an f-Secure linux boot, antivirus disk, I managed to clean my system and get rid of them.
I would not recommend using the f-Secure linux disk unless you know what you are doing as it will rename any rootkit or virus it finds and if the infected file(s) happen to be needed by the system, your computer may not work after using this antivirus software. So be warned! Every situation is different.
If you think you may be infected with malware you have come to the right place! However...
Do not use ComboFix unless requested by an expert. Your computer may not ever work again!
Best to post your information in the "Am I Infected" thread.
Include as much info about your problem and your computer as possible. Read the pinned topics in the "Am I Infected" thread.You must be patient!
This is one of the busiest forums on the internet helping people fix these problems and the expert, knowledgable people helping are volunteer's! They will help if they can.
The less you use your computer at this point, the better. Some malware can spread from file to file as you use your computer.
I have yet to find any concrete way to stop Drive-by downloads from happening before the fact. but...
Keep your operating system up-to-date, use a firewall, use good antivirus (like avast!), antimalware (Malwarebyte's AntiMalware), antispyware (SuperAntiSpyware), keep them up-to-date, and you will at least have some protection. Any protection is better than nothing, some are better than others.
The bad guys always seem to be one step ahead of the latest protection but the good guys will prevail!
And if anyone has any ideas or thoughts on preventing Drive-by downloads I would really like to see them.
Be careful out there.