First of all, please excuse my spelling mistakes. If this is not the correct website for my question, just let me know.
I have a perfectly fine owncloud instance running on my raspberry pi, connected to the internet via a DDNS service and a CNAME Record on my own domain. The Desktop client worked without problems for a few months now. Additionally, the server is SSL secured by symantec.
Today i got a very weird message: The ssl certificate doesn't match my domain. Owncloud desktop stated that the certificate was for somedomain.spdns.de, while my actual domain is (something like) www.mywebsite.de. I've attached a screenshot of the error message to this post.
When accessing www.mywebsite.de chrome states, the website is secure and the certificate matches the domain name. I've never seeen somedomain.spdns.de in my life.
Is someone trying to get into my owncloud? If yes: How and what can I do? If no: Why am I getting this error message?
Operating system: Raspbian Linux v. 4.9.35-v7
Web server: Apache 2.4.10
Database: MySQL 5.5.57-0+deb8u1 - (Raspbian)
PHP version: 5.6.30-0+deb8u1
ownCloud version: 10.0.3
Storage backend (external storage): 128GB USB
Client version: 2.3.4 (build 8624)
Operating system: Windows 10 64 bit
OS language: German
Installation path of client: C:\Program Files (x86)\ownCloud
The log files don't seem to help at all.Please excuse my spelling mistakes. if this is not the correct website for my question, please let me know.
Thanks for your help! Let me know if you need any additional information.
I discovered, that the ip-address, somedomain.spdns.de points to is the same ip, my home network had yesterday. Is it possible, that Owncloud Desktop doesn't check the DNS entry for my dynamic dns service frequently enough, so it points to the person who gets the ip assigned next?