Spysweeper's Common Ads Sites shield adds many sites to your hosts file. The
purpose is to block ads from those sites from appearing on your computer.
They are harmless. Are you using Spybot S&D in Advanced Mode? If you are,
Spybot has a tool that adds dangerous sites to your host file so that you
cannot navigate to those sites and get infected by malware. These are safe to
have in the file. I would not add any others until you study more on the
subject.
The entries from Spybot should look something like this, but many more of
them:
# Start of entries inserted by Spybot - Search & Destroy
127.0.0.1 babe.the-killer.bz
127.0.0.1
www.babe.the-killer.bz
127.0.0.1 babe.k-lined.com
127.0.0.1
www.babe.k-lined.com
127.0.0.1 did.i-used.cc
127.0.0.1
www.did.i-used.cc
127.0.0.1 coolwwwsearch.com
127.0.0.1
www.coolwwwsearch.com
127.0.0.1 coolwebsearch.com
127.0.0.1
www.coolwebsearch.com
127.0.0.1 hi.studioaperto.net
The entries from Spysweeper should look something like this, but many more:
27.0.0.1 ads.astalavista.us #SpySweeperCASS
127.0.0.1 ads.belointeractive.com #SpySweeperCASS
127.0.0.1 ads.bfast.com #SpySweeperCASS
127.0.0.1 ads.bianca.com #SpySweeperCASS
127.0.0.1 ads.bigcitytools.com #SpySweeperCASS
127.0.0.1 ads.bitsonthewire.com #SpySweeperCASS
127.0.0.1 ads.bloomberg.com #SpySweeperCASS
127.0.0.1 ads.cashsurfers.com #SpySweeperCASS
I would suggest downloading Hoster from Funky Toad and using it to get a
better grasp on what's in there.
OR go to Spysweeper Hosts File shield and check "edit hosts file." It will
show you everything in there also.