At first I thought it was High Sierra as I have only just upgraded but it then occurred to me that it could be iStat Menus. I close the lid and expect it to go to sleep. I was very surprised this morning to find that my MBP was warm as if it had been active overnight. It works OK and I was happy with the summary on the menu bar. Looking at reviews iStat Menus seemed quite good. I tried XRG and didn't think too much of it.
I looked at Activity monitor which is just too much info. Main reason I am trying it is that I want a replacement for the discontinued widget iStat Pro just so that from time to time I can look at aspects of the machines performance. I have just downloaded and installed iStat Menus as a 14 day trial.
