This was studied a few years ago as "parasitic computing": https://en.wikipedia.org/wiki/Parasitic_computing https://en.wikipedia.org/wiki/Parasitic_computing

This was studied a few years ago as "parasitic computing": https://en.wikipedia.org/wiki/Parasitic_computing https://en.wikipedia.org/wiki/Parasitic_computing But it's a bit strange that the same broad concept can include subtle things where the indirect result of an activity is a computation that someone else wanted you to make, along with explicit cases where someone asks your device to run a full-fledged applet and it does so (to someone else's benefit).