It should be written in any native language you think is the best.
.doc and .xls should be FUD.
I need to test it before releasing funds.
It should use unique or advanced storage methods.
FUD time should be very long due to it being metamorphic
Able to bypass Scan time, Run time and Windows defender.
It should only have basic features of an Exploit, such as select file and exploit. You can add any other feature if you think it is needed.