Malwarebytes reported on 2-Feb-2018 that MacUpdate.com was hacked and some ( Firefox, OnyX, and Deeper ) applications were maliciously-modified. MacUpate corrected the issue on the same day. Saw this initially on Macintouch
The same here, I don't trust site (or service) that requires that I have an app to install apps that I can get from the developer directly. This isn't the first time, macupdate has been infected by malware, and even if it wasn't, I'd still avoid them.