Browser redirects to coo123.net When I open my tablets browser to yahoo it automatically redirects to coo123.net page. How do I stop that from happening?
Delete the entry for yahoo in the host file. (It's most likely here it's happening)

Here's how:
http://www.techrepublic.com/article/edit-your-rooted-android-hosts-file-to-block-ad-servers/

Essentially:


Use a file manager like ES File Explorer
Locate the file /system/etc/hosts
Remove the line that says anything about yahoo
Save the file
Reboot


If it doesn't work make sure that the file has the correct permissions:


  
  Open ES File Manager
  Navigate to /system/etc
  Locate and long-press the hosts file
  Tap the menu button
  Select Properties
  Tap Change in the Permissions section
  Tap the check box for Group under the Write column (Figure B)
  Tap OK
  Tap Cancel
  Reboot device
  


(Quoted from techrepublic)