I just ran Virus BarrierScanner on my Macbook Pro Retina Early 2015 (I was suspicious that I might have a virus).
It identified 12 files as malware, and they are all called "imagesnap."
The parent folder is a hidden folder called usr... and one subfolder is called prey. and the 12 files are in 12 different version folders, named 1.6.6, 1.6.8, on and on to 1.8.3.
All of these things lead me to think it might be PREY, but I don't know how to be sure because I'm not a really techy person. If this is prey, great! If not, I'll have to get these off my computer.
See screenshot compilation below for the scanner idenitifed files, and the file locations.