Call it what you want but these are just a pain to deal with. I have people call me about all of these things frequently, and its usually a conversation that spans two or three days. Currently, I'm working on the Spam problem. However, let me start with HiJackers.
Hijackers: Programs that hijack your settings changing thins such as your home page (start page), default search engine, et. al.
The most prevalent of these I've seen is CoolWebSearch or CWS. This particularly virulent pest has nearly 40 variations and a special program designed to remove it specifically. You can read about it at
here.
LOP or Live Online Portal is another prevalent parasite see articles about it
here and
here
These types of programs can do even more malicious things. Some will replace legitimate ads on a site and replace them with its own or an affiliates, this is bad because it is stealing advertising dollars from sites that you are supporting. Some will even change the actual link target on pages you're viewing to such things as porn sites, dialers, etc... so that when you click on a link you get redirected to these sites. They can add links to your favorites list, usually porn or such. Generally they are just bad news.
The one piece of advice I can give is don't click on links on pop up ads. Close them using the X in the upper right corner. If that option is not available, press ctrl-alt-del, open the Task Manager and choose the browser application and close.
For information about browser hijacking, what it does and how it works, see this
article.
For prevention methods see this
article.
I also suggest downloading these programs.
Ad-aware,
PestPatrol,
SpySweeper,
Spybot S&D
Now on to popups...
Popups: Ads that pop up in a separate window when you are surfing the web.
While there are several different Popup blockers out there to choose from, I prefer the following IE Toolbars.
The
Google Toolbar
and
The
Yahoo Toolbar
These both do an effective job of blocking popups, while providing some other useful functions. The Yahoo Toolbar is even more effective if you have a Yahoo account and have personalized your Yahoo content.
I'll be updating this post as I learn more about spam filters.
SPIFF