Avast downloading unsigned document .png files.

When searching google images, any images right-clicked on and “Save to downloads” is selected will download as a unsigned (.txt, .png) file by the name Unknown.

The Mac classifies it as a TextEdit Document, however changing the extension to have .png allows it to be correctly displayed as a photo, however the data size was cut down to a measly 2-3kb.

Anyone else experiencing this?

I can reproduce the bad file naming even when Avast is not running, so it is
most probable a Finder/system issue rather than Avast’s issue.

Btw. - what do you mean by “unsigned document .png files”?