Hi Jonas,
Thank you very much for taking my extension into consideration!
I will try to solve all your doubts:
Brute-force attacks
Yes, the
backend protection feature will hide the backend, preventing brute-force and dictionary attacks.
Dynamic blacklist feature will also block offensive IPs after some attacks.
Mysql injections
Yes, Securitycheck Pro protects you against mysql injections, Cross-site scripting, Local File Inclusions, Remote File Injections, unauthorized uploads, HTTP header attacks, and so on...
Denial of Service (DoS)
Dynamic blacklist blocks offensive IPs after a certain number of attacks; this would prevent some Denial of Service attacks, but no extension can fully prevent attacks like this. You need the help of your hosting provider to fight against this kind of attack, because it involves his network infrastructure.
scans POST and GET variables
Yes, it check both methods.
Also, do you have a site backup feature?
No, currently I don't provide this feature.
Regards,
Jose