I ran into this site www.magereport.com and it checks for vulnerabilities, but I wanted to see if it is a trusted site or authorized by magento.
Thanks in advance,
From the looks of it; it's registered to a company in the Nederlands called https://www.byte.nl/. Its likely not endorsed by Magento themselves but It looks fairly legitimate in what it does / tests for.
As I mentioned in another topic, it seems magereport shows some false positives.
For example it says my site is vulnerable to shoplift but I'm sure it was patched...
It's a good starting point anyway.