I just uninstalled NiceHash and will never use them again. Lost $10 doing so (below their minimum withdraw limit) but not interested in supporting them in future. Small loss

I downloaded NiceHash on the 27th of February and on that day it was the legit 5.5c version. There is a third question of course - does the "real" 5.5c contain a virus or trojan. Only time will tell....it is not exactly open-source for scrutiny. I will continue to run it on a stand-alone box in my DMZ as any such app should be.

As previously stated I am a newbie in mining of just one month. I set up an unused pc and threw a couple of unused GPU's in it and then followed the steps listed over at ethermine.org - choosing PhoenixMiner from their suggested list. I downloaded 5.5c from their link, which points (and still does) to this forum's link, now no longer available. The SHA-256 sigs match those revealed here by legit users.

AND on the 27th of February a few weeks back, I randomly downloaded and tested NiceHash for an hour, which brought with it PhoenixMiner and some others. When I look at the checksums of the version NiceHash downloaded, it is certainly the legit and identical version to that running right now, which I downloaded from here. It even has the stock wallet address of: 0x008c26f3a2Ca8bdC11e5891e0278c9436B6F5d1E.Rig001

So as of that date (27-02-2021) NiceHash was delivering the same "clean" version 5.5c and not the bogus 5.5d

Ethermine.org is still recommending it in their website. I have the archive downloaded from a few weeks back if it is of any use to anyone.