Real world polymorphism Polymorphism is easy to achieve via simple programmatic logic in phishing kits. By using templates and wordlists, actors are able to quickly generate similar, but slightly different emails en masse. The predominant advanced actors in the phishing landscape, however, have figured out an even better method for creating unique emails. 

Emotet, QakBot, and others have been using stolen emails at a massive scale for some time now. Beyond having unique subjects, their typical phishing emails will have unique bodies, constantly changing payload hashes, and payload URL’s.