You either didn't read your own link, or didn't understand it - NP++ uses a DLL that could be separately backdoored; the backdoored version wasn't shipping with

You either didn't read your own link, or didn't understand it - NP++ uses a DLL that could be separately backdoored; the backdoored version wasn't shipping with NP++ installations. You could in theory do something similar with literally any Windows application that links a DLL (i.e. virtually all of them).