I have been scanning the website at Magento Scan and getting the following error:
Magento Compromise Injection
In page source I can clearly see a malicious script included in header.
After further research I found that there are entries in core_config_data with path : 'design/head/includes' and the value column has that malicious script.
I have not changed nor uploaded any extensions.
This has happened 3 to 4 times earlier and I am able to track how is this being injected.
When it happened for the first time and for every other times, I have changes database credentials but it didn't helped.
What measures should I take to prevent this?