What does most malware do? It tells you you are in sudden danger when you are not, in order to scare you into buying something.
That by itself doesn't mean a program is malware. It takes more. Like the following:
(1) When you install Malwarebytes Free, it defaults to the 14 day Premium Trial.
(2) When the trial runs out, a warning appears that is intended to scare users into buying the Premium version -- a warning that implies the user is in imminent danger.
(3) If users downgrade to the Free version, it gets switched back to Premium (and re-starts the 14 day countdown to the scareware message) EVERY TIME you do a full upgrade.
(4) Full upgrades seem to be more and more frequent...
Now this last one might be a necessity of battling modern malware. But when you combine all four you get something that looks a lot like a virus. At the very least, it's disappointing.
"HOW CAN FREE STUFF BE DISAPPOINTING?" Because we're spoiled by good free stuff. But MBAM also makes $, yeah? (You must -- I've advised many virus-prone clients to pay for MBAM.)
And it's good to get paid. Especially if you deserve it because you made a light, fast, effective, safe cleaner and made it available for free.
But beware the road that so many have taken. AVG --> Crapware Bloatfest. Avast --> Turdpile Scumbladder. There's more but I'm lazy. Oh yeah -- Norton. Yes I invoke Norton, the Nazis of fake security. Decade after decade, trusting grandpas gently shell out $50-$100 per year for one of the worst AV programs in history, just because, once upon a time, Norton was clever enough pay HP and Dell to infect countless generations of PC's with "Free 90 day trials" which ended with, you guessed it, scary warnings. (Another Norton tactic: they convince journalists that Norton is the go-to authority on malware. They conduct interviews in "war rooms" -- big darkened high-tech workspaces full of busy technicians toiling under giant screens that show the global progression of "the threat". Jesus.)
PS - How long till Adwcleaner starts having nag screens about the pro version?