If you first execute rkill.exe but the command prompt window did not open, you should keep trying to open rkill.exe. During this review, rkill.exe did not open at all. After few tries in executing rkill.exe, it able to bypass the malicious processes of Security Tool and succeed in terminating the offending processes.
If rkill.exe continue to not to run (after you’ve tried few times), you can proceed to use the other file format of rkill one at time until one of the file formats of rkill succeeded in terminating the malicious processes.
If in any event that none of rkill format will help in terminating the fraud tool processes, you should go to BleepingComputer.com’s Malware Removal forum for further assistance.