www.lavasoft.de
or via
www.download.com look for Spybot and or Adaware
that 217.12.4.96 ip is from Yahoo. so there is something dodgy on your computer
also have you got a Firewall if not get ZoneAlarm.
the 192.168.0.143 is something in your own local network so most likely your own computer which has spyware and stuff like that on it.