If you are experience with random pop-up ads from adcash.com within Internet Explorer, Firefox and Google Chrome, then your computer is infected with a potentially unwanted program.
If you already trying disable unwanted add-ons, extension But the problem still persist then you can do following step
1. If you use firefox then add BlockSite Add-ons
2. Add adcash.com in the block list.
3. Restart the firefox.
This is temporary solution. You should continue to find unwanted program in your PC and try to remove it.