Log/list of external/unauthorized programs that were given permission to open
I did a grep -iR for one of the names I recalled and one of the files it turned up in was: /Volumes/HDD1/Library/Receipts/InstallHistory.plist, HDD1 being the name of the drive the OS is installed on. So happy to have found it, because Apple increasingly hides all this useful info from users. 

This is a file with complete records with names of all installed programs and the dates they were installed on and some other info.