Dear Eddy
Thanks for the idea. I have scanned again the whole system, but the file did not change its properties. Avast did not find any infection neither this time (48 files could not be scanned, but this is as usual). Anyway, I still think that it is too much coincidence that the file was created just two minutes after I began that previous analysis that I mentioned, and there is another user who relates this with Avast and claims that the file was back when he scanned again his computer with Avast (link in my first post).
Any idea of what this may be and any suggestions of what should I do?
Thanks for the support
Tahl