There is one infection that malwarebytes can't detect and that is an mbr/boot infection. Please download and run TDSSkiller.
Please download and run
TDSSkiller
When the program opens, click on the start scan button.
TDSSKiller will now scan your computer for the TDSS infection. When the scan has finished it will display a result screen stating whether or not the infection was found on your computer. If it was found it will display a screen similar to the one below.
To remove the infection simply click on the Continue button and TDSSKiller will attempt to clean the infection.
When it has finished cleaning the infection you will see a report stating whether or not it was successful as shown below.
If the log says will be cured after reboot, please reboot the system by pressing the reboot now button.
After running there will be a log that will be located at the root of your c:\ drive labeled tdsskiller with a series of numbers after it. Please open the log and copy and paste it back here.
Then afterwards, rerun malwarebytes full scan and post its log and post a hijackthis log as well.