tmpForThumb

[amorino]

Hello,
in my virtuemart directory :
components/com_virtuemart/shop_image/product

I found so many files that begin with : tmpForThumb_php

For example tmpForThumb_php3Itdkq

and in the directory
components/com_virtuemart/shop_image/product/resized
I found mani files that end with :
.jpg0000644

For example T_SERIES_TIP_4f1eb9eb4caf5_150x150.jpg0000644

What are these files?
Could I delete them?
Best regards
Amorino