Q: My Macbook Pro seems to be infected with virus.

1. Use  free Malwarebytes Anti-Malware for Mac/ AdwareMedic to remove adware

     http://www.adwaremedic.com/index.php

   Download, install , open,  and run it by clicking “Scan for Adware” button   to remove adware.

   Once done, quit Malwarebytes Anti-Malware.

   or

   Remove the adware manually by following the “HowTo” from Apple.

   http://support.apple.com/en-us/HT203987

  2. Disable Extensions and test.

    Safari > Preferences > Extensions

    Select and dissable all extensions and test.

    Enable Extensions one by one and test.

    To uninstall any extension, select it and click the “Uninstall” button.

3. Safari > Preferences >  Search > Search Engine :

    Select your preferred   search engine.

4. Safari > Preferences > General > Homepage:

     Set your Homepage.

You have adware, not a virus.  There are no viruses out in the wild (right now) that can damage OS X.  You probably got it from downloading something you shouldn't have from some place you shouldn't have.  In the future, avoid the following kinds of sites:

• XXX sites
• torrent sites
• aggregate download sites (CNET, Softonic, MacUpdate, Download (dot) com, etc.)
• mp3 download sites (Mp3Skull, mp3monkey, etc.)
• any site that says you can download something for free that you know otherwise costs money

Safari/Browsers - Eliminating browser redirects and advertisements

Safari/Browsers - Eliminating browser redirects and advertisements (2)