My Linux instance got disabled by Oracle for adding port 22
I'm having an Oracle Cloud instance with shape 'VM.Standard.E2.1.Micro' and Kali Linux as OS. The instance has been created just few days ago. Yesterday I got a mail from Oracle saying that my instance has been disabled as they detected unusual and potentially harmful activity. The following is the traffic details mentioned:
Traffic Details: Outbound Port Scanning, Brute-forcing, Web Exploitation, and/or DDoS.
It's also mentioned the activity happened through port 22.
I've actually enabled port 22 in my instance subnet by adding ingress rule and gave source as '0.0.0.0/0'. I did this so that I can access my instance through SSH. But now, Oracle disabled my instance. Can someone please let me know why this happened and is there any way to do this safely?