Came across this: https://en.wikipedia.org/wiki/List_of_rogue_security_software
Wikipedia currently has the following definition for "Rogue Security Software":
a rogue (a form of Internet fraud using computer malware) that deceives or misleads users into paying money for fake or simulated removal of malware (so is a form of ransomware) — or it claims to get rid of, but instead introduces malware to the computer.
Not sure how up-to-date the list is.
Found some other lists that seemed clearly out-of-date by a year or more.
Apart from asking around, I guess if one is considering something for installation and it's small enough jotti, virustotal, and the like are likely to give useful feedback about the candidate in question.