Thanks Marcos,
when I opened the doc the first time no popup warning was displayed by Nod32, is it possible that something has been installed at that time ? After having realized this, I performed full scan with Nod32, Spybot s&d, Zemana, Malwarebytes and HitmanPro, but they didn't find anything serious. Can I consider my PC clean or I should perform a deeper analysis (and in case how) ?
Thanks again, Z.