isass.exe definition, relationships, removal:

File isass.exe is the main component of the backdoor, which is a variant of OptixPro backdoor. isass.exe is an executable file that is responsible for launching parasites, loading main components of malicious programs and running a destructive payload. It is a significant part of a dangerous parasite, but can also function as a stand-alone threat. DO NOT run this file!
The isass.exe file is installed and used by Pahatia.
You have to delete the isass.exe file immediately after you have found it. The parasite will continue to violate your privacy and harm your computer unless isass.exe and all related objects will not be completely removed from the system. If you have difficulties erasing the file consider using an anti-spyware program.
Sometimes a presence of isass.exe does not indicate that your computer is infected. It can be an essential system file or a file installed by harmless legitimate software and therefore may not pose any threat to your privacy and the system. Although such cases are quite rare, you should thoroughly examine isass.exe before completely deleting or leaving it in the system.