So I just bought a shiny new VPS and I've installed a LEMP stack (NGINX) and WordPress. It's been up for a couple of days now and I decided to browse the access logs. Inside, I found several rather concerning log entries similar to below:
[IP address redacted] - - [09/Mar/2016:22:28:02 +0100] "GET [foreign domain name redacted] HTTP/1.1" 200 41 "[same foreign domain name again, redacted]" "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)"
Now I understand that any public-facing server is inevitably bound to be inundated with script kiddies probing for vulnerabilities.
However, I find the 200 response code to be concerning. Am I correct to think this?
What are they doing, why are they doing it and how? Above all, how can I prevent it?