I vaguely recall some kind of malware that upon infecting a system scanned the system for other malware and removed/disabled it. The motives were far from pure,

I vaguely recall some kind of malware that upon infecting a system scanned the system for other malware and removed/disabled it. The motives were far from pure, obviously. (Although there also was a case, I think, of a piece of malware specifically created to ensure "infected" system had up to date AV software and were up to date update-wise. We sure live in strange times.)