If you’re trying to recover the original filename, it’s likely:

The original text appears to be:

It looks like you’re trying to parse a filename that may have been corrupted or scrambled.

And then something like was appended, possibly by accident (e.g., from a file splitter, misnamed download, or text encoding issue).

The extra part could be a segment number (e.g., from a split archive), and "downgrade serif venu" might be random text or leftover metadata.