Are files being opened while converting .doc(x) and .xls(x) ?

[adwul62]

When I r-click a .doc(x) file and select 'Convert to PDF' it seems(!) that Microsoft Word is -not- launched.
I am not sure though, it is going too fast to verify.

OTOH when I do the same with an .xls(x) file, I see Excel being launched in the background. It is visible for maybe a second or so and then disappears again.

Whilst I do not see Word being launched, Excel indeed shows up, be it for a very short moment.

Question: is Word also started when converting the .doc(x) file?

Background: those documents are sent to me being a member of some club. Most likely they do not contain viruses, but I am not sure. I have a decent AV in place and I could have each file checked by Virustotal, but I considered to skipping all that and rather convert them to PDF just to make sure.
This does not make sense when Excel is started nonetheless.

[radzmar · Accepted solution]

The conversion into PDF requires to open the source file in its nativ application first. There it's then passed to the PDF plugin, which will create a PDF then.

[adwul62]

Sorry for the delay. 
Thanks for the reply. I more or less assumed so.
Thanks again!