your Computer may be infected ! or host file got malware did you run a malware scan ? give this a try http://www.adlice.com/softwares/roguekiller/   and make sure you clear the host file after RogueKiller done the scan !
 and make sure you clear the host file after RogueKiller done the scan ! 
if RogueKiller doesn't fix your problem then give combofix a try http://www.bleepingcomputer.com/download/combofix/ 
Hosts File looks pretty normal too me;
# Copyright (c) 1993-2006 Microsoft Corp.
#
# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
#
# This file contains the mappings of IP addresses to host names. Each
# entry should be kept on an individual line. The IP address should
# be placed in the first column followed by the corresponding host name.
# The IP address and the host name should be separated by at least one
# space.
#
# Additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a '#' symbol.
#
# For example:
#
#      102.54.94.97     rhino.acme.com          # source server
#       38.25.63.10     x.acme.com              # x client host
127.0.0.1       localhost
127.0.0.1       investorshub.advfn.com
127.0.0.1       finance.yahoo.com
127.0.0.1       google.com/finance
127.0.0.1       money.msn.com/investing
127.0.0.1       
http://money.msn.com/investing/127.0.0.1       
http://investing.money.msn.com/127.0.0.1       ckmap.mediav.com
127.0.0.1       pv.sohu.com
127.0.0.1       
www.zhibo8.cc127.0.0.1       
www.0086best.com127.0.0.1       show.g.mediav.com