I run Windows 10 (Version 1607, Build 14393.969) with up-to-dated Bitdefender Total Security 2017 and MalwareBytes Anti-Malware Home (Premium). There is no pirated software installed on the computer.
Less than 15 minutes ago, I saw 2 command line windows opening and closing very quickly on their own. I was just browsing the web and had not just restarted the machine. The first window appeared and disappeared too quickly so I couldn't see what was its content. For the second one, I only managed to see the words "ubuntu" and "multiverse" before the window closed by itself. The only "linux-related" things I have on this machine is Bash on Ubuntu on Windows and TightVNC with the latter running in the background.
How do I please figure out what happened? Specifically, which program / process opened those command line windows and, if possible, what command lines were being run? I saw this earlier post here and the comments focused on programs / processes that run on startup but I haven't restarted this machine for some time. I also installed ConEmu (Ver 161206) but so far has been unable to follow the instructions in the answer.