>it needs to be a sort of viral botnet
Very close. Think more like bacteria evolving in your gut. If you ingest different foods, you will end up with different bacterial ecologies…
Imagine thousands of simple chatbots randomly generated. Only a few might succeed at a certain task. In that case, reproduce more chatbots similar to the successful models, with some random mutations. Rinse and repeat.
This way you have a freely evolving botnet which will be effective without requiring intensive data collection or analysis.
I imagine there are also monolithic AI's that engage in the kind of intensive analysis >>146529 discusses, but the freely evolving botnet which reproduces successful bots with small mutations is also there.
tl;dr there are "r-selected" and "K-selected" AI's on the internet