LOL.
Beware of URL spoofing. It's not clear where that "memorandum" actually resides.
Memo is at https://www.courthousenews.com/wp-content/uploads/2017/06/trump-docs.pdf The courthousenews.com domain is anonymous, but real enough. Their standard procedure at that website is to store documents in a wordpress content directory. They have numerous court filings stored with similar URLs, e.g. https://www.courthousenews.com/wp-content/uploads/2019/03/Deripaska.pdf There's no reason to believe that the content is from any other source than courthousenews.
That still leaves the question of who courthousenews is, but they seem legitimate. Also the question of the context of the Trump document, or other Trump documents that they have not published, etc. We don't know the provenance, but we also know the MSM would never bother validating such a document due to their 1) bias 2) laziness and 3) ignorance. So I would not discredit the sourcing at this point.