What should I do with mongodb security installed in aws ec2? I using aws linux freetier

When I entered my site today, mongodb all collection was drop... OTL

(I checked the global log and confirmed that the Chinese ip dropped...)

When I installed mongodb, my /etc/mongod.conf setting

# network interfaces
net:
  port: change my port num
  #bindIp: 127.0.0.1
security:
    authorization: enabled


next i was aws security group open and write my port num and anywhere setting

Is this a problem? What should I add more? 
Please teach me
Here is a few things to read up upon:
https://docs.mongodb.com/manual/administration/security-checklist/

In your mongo.conf its good to disable the REST API and http interface.

Use a non default Mongo port e.g not 27017 and use AWS security groups to only allow that port to a given IP not to the world.