What you should do at this point is download the the full Joomla install file from Joomla.org for the version your using. This will have the 'original' framework.php file in it. Then, use a comparison tool (WinMerge for Windows, diff for Linux, or one of many more) to see what's different between your copy and the original.
If the changes are not your own, you should hopefully be able to simply copy the 'good' file into your site. If you feel the changes were done by a hacker, you should really perform a security audit of your site to determine how the change was made, and if any other changes have been made that you should be aware of. These changes could be the creation of a Super Admin you don't know about, modification of other non-core Joomla files that could allow access to your site, or addition of files that can leave holes in the security of your site. Much of that is outside the scope of this forum, but hopefully will get you started.
If they are yours, just make sure that you still want them, and if so, leave them be.