Tab Hosts?

Hosts tab is used for easier management of "hosts" file. It's used to redirect website addresses to other IP address. These entries you were talking about, those entries were created by immunization (by either Spybot-S&D or SpywareBlaster). Those entries are not threats. They are redirected to 127.0.0.1 (or 0.0.0.0 is possible too) which is localhost which causes to block those sites. Malware uses hosts file, too and it mostly uses it to block access to security websites.