How to fix EC2 Abuse Report

I have got email from AWS that one of my EC2 is infected with malware and may be part of botnet. Can someone please guide me on how to fix this ?

Please investigate this reported activity from your AWS Resource.

Destination IP: 194.145.227.21 Destination Port: 5443 Please Review - https://cujo.com/the-sysrv-botnet-and-how-it-evolved/