Is it possible without installing any Monero related packages on my Ubuntu 16.04 laptop with a gforce gtx 960m, that I have a monerod process running, started by root? Any virus?
If you did not install monerod, then someone else did, and it's likely malware. It seems surprising for two reasons, however:
Therefore, the most likely explanation is that you or someone who uses your computer installed Monero software.
One thing to note: the Monero GUI wallet can start monerod automatically, so if you tried it, this might be why.