If you use Wordfence, and it is telling you that http://login.microsoftonline.de/common/oauth2/v2.0/authorize (found inside UpdraftPlus’s OneDrive code) is a phishing URL, then please rest assured that this is untrue. It is the official Office365 (including OneDrive) authentication URL for Microsoft Germany. You can verify this at the official page on microsoft.com, here.
If you get this report, then please do report this to Wordfence if you can. The number of times that Wordfence flags false positives in different places is a non-trivial support burden (and last happened under two weeks ago), as well as surely being an annoyance to Wordfence users who value their time.
We recommend that Wordfence users suggest to Wordfence support that they test all their anti-virus rules upon the most popular WordPress plugins before releasing them to their end-users.
David Anderson (lead developer)