Increasingly we see popup boxes and notices that look very much like typical Microsoft or Adobe update notices.. but are for things you don't want. You find a video you want to watch, but it says it requires a specific video player or video update to play. Chances are getting better and better that it is a attempt to install something you do not want or need - something that will be a pain in the rump to remove from your pc. And even if they do no real harm, they clog up your system and slow it down a bit with each piece of unwanted garbage you install.
Bundleware - the practice of giving you "free extras" when you download something that you want and would likely trust otherwise - extra toolbars, programs to check your system for faults (that don't or do a poor job) and driver update tools - these are getting more common.
My favorite to grumble about lately is the way search engines favor paid advertisers at the top of your search results. While its a basically good idea - it has gotten used to be very mis-leading and downright dangerous in some cases. Take any good malware cleaner program - or even the popular remote control program "TEAMVIEWER" for example. If you search for that word, you may get several matches from paid advertisers - but the actual site for www.teamviewer.com is listed much lower down. If you go to some of the others, you may get the TEAMVIEWER program but it may not be the official (and safe) version. They may come with extras that you don't want. Likewise when you seek SPYBOT or MALWAREBYTES - both well known and usually safe free programs.
An article I found today on CHANNELPRO.COM also warns about the common searches on Google that come with many dangerous results. It's well worth a quick look here. And another good short read on just bundleware is here at PCFIXES.COM
