All network printers are printing gobblety-gook. Starts with GET /HTTP/1.0

I have 4 spiceworks deployed on the network. 1 *was* a network scan and 3 were just used for the ticketing system. Recently I deployed a BitDefender Anti-virus and Ninite. Besides those products listed, there's nothing on the network that is legitly doing scans on the network. What could be doing this to trigger printouts on each of my printers? And how do I sniff it to figure out what app/computer/source is causing it?