data.langly.fr has the post in English and very well written
The hacker writes well and explains how he owned (penetrated) the website
gamma-international.de, which redirects to finsupport.finfisher.com
The hacker 31337 explains himself including how to stay anonymous, and not reveal who you are to the site that he attacked.
He uses Google tricks including the “inurl:” search
SQL injection was used to hack the site and it worked right away.
He also attached a file to a support ticket, with no check on file extensions, so he attached:
“So I pick a username and password out of the customer database, create a support request with a php shell
attached, and I’m in!”
this is the problem, nobody tested the SQL injection vulnerabilities (pretty easy to do)
Then nobody tested adding a php file extension file addition. And now the system is hacked.
We can help you test your systems