I’ve been asked couple of times recently about Phorm, NebuAd and similar technologies, so here’re some links to get you started.
The following two transcripts of some Security Now episodes from Steve Gibson of GRC (Steve coined the phrase ‘spyware’) give a good intro.
http://www.grc.com/sn/sn-151.htm
http://www.grc.com/sn/sn-153.htm
This is the vendor that’s caused the most ripples… used to be called ’121media’, if you know anything about spyware this will cause your hair to stand on end:)
http://www.phorm.com/
More links…
http://www.theregister.co.uk/2008/02/29/phorm_roundup/
http://en.wikipedia.org/wiki/Phorm
http://phormwatch.blogspot.com/
http://www.nebuad.com/