Multiple Word Search in Plain Text

Multiple word search using Plain Text produces matches with ANY of the search words. This makes it impossible to narrow down a search range when using content inside documents.

Searching content (Plain Text) should produce only items with ALL search words. For example, searching for the word RED BOX should only show documents with content containing both names, not all documents with either RED or BOX.

Note : This is already the search behavior in WP File Download when not using the Plain Text option (searching titles for example) which is correct. It is the behavior of most search tools (eg Google)