Reduce the probability of a breach by checking EC2 security groups for inbound rules that allow unfettered access to TCP port 135 (used by Microsoft Message Queuing (MSMQ) and other Windows software) and restrict access to IP addresses that require this port.
Malicious activity, such as backdoor command shell hacking and denial-of-service (DoS) attacks, can occur when permitting unfettered access to this port.