“One forum user claimed to have had suspicions of REvil’s tactics, and said their own plans to extort $7 million from a victim was abruptly ended.”
REvil rents its ransomware to affiliates and hid a backdoor in it so it could grab the payouts itself. Now the affiliates are on a forum complaining about trust. They will keep signing up anyway, because REvil pays best. The victims pay the same either way. The only open question is which crook keeps the money.