So my previous alma mater's IT servers are really hacked easily. They run mostly in Microsoft Windows Server and Active Directory and only the gateway runs in Linux. When I checked the stationed IT's computer he was having problems which I think was another intrusion.

I asked the guy if I can get root access on the Gateway server. He was hesitant at first but I told him I worked with a local Linux server before. He jested, sent me to the server room with his supervision. He gave me the credentials and told me "10 minutes".

What I did?

I just installed fail2ban, iptables, and basically blocked those IP ranges used by the attacker. The attack quickly subsided.

Later we found out it was a local attack and the attacker was brute forcing the SSH port. We triaged it to one kid in the lobby who was doing the brute forcing connected in the lobby WiFi. Turns out he was a script kiddie and has no knowledge I was tracking his attacks via fail2ban logs.

Moral of lesson: make sure your IT secures everything in place.