I recommend you UnHackMe - Ultimate Malware Killer for fast malware removal:
Free Download Fully Functional 30-day Trial. No credit card is required.
Reviews. EULA. Privacy Policy. Uninstall.
The file KOJA.EXE is malware related.
You must delete the file KOJA.EXE immediately!
Delete the file KOJA.EXE without delay!
Kill the process KOJA.EXE and remove KOJA.EXE from the Windows startup.
KOJA.EXE Information and Removal:
MD5 of KOJA.EXE = 3F36591BBD57BC8B64A957419AFD4864
KOJA.EXE size is 172544 bytes.
Full path on a computer: %APPDATA%\GAGYH\KOJA.EXE
Related Files:
%APPDATA%\GAGYH\KOJA.EXE
%APPDATA%\YRAR\BUIZ.WUE
%APPDATA%\YRAR\BUIZ.WUE.0
%TEMP%\TMPAE1BAC80.BAT