T1048.003 Exfiltration Over Unencrypted/Obfuscated Non-C2 Protocol Mappings

The following GuardDuty finding type flags events where adversaries may steal data by exfiltrating it over a different protocol than that of the existing command and control channel. Trojan:EC2/DNSDataExfiltration Behavior:EC2/TrafficVolumeUnusual

The following AWS IoT Device Defender device-side detection metrics can detect indicators that an adversary may be exfiltrating collected data from compromised AWS IoT devices over a given channel to/from those devices: "Destination IPs" ("aws:destination-ip-addresses") outside of expected IP address ranges may suggest that a device is communicating with unexpected parties. "Bytes in" ("aws:all-bytes-in"), "Bytes out" ("aws:all-bytes-out"), "Packets in" ("aws:all-packets-in"), and "Packets out" ("aws:all-packets-out") values outside of expected norms may indicate that the device is sending and/or receiving non-standard traffic, which may include exfiltration of stolen data. "Listening TCP ports" ("aws:listening-tcp-ports"), "Listening TCP port count" ("aws:num-listening-tcp-ports"), "Established TCP connections count" ("aws:num-established-tcp-connections"), "Listening UDP ports" ("aws:listening-udp-ports"), and "Listening UDP port count" ("aws:num-listening-udp-ports") values outside of expected norms may indicate that devices are communicating via unexpected ports/protocols, which may include exfiltration of data over those ports/protocols. Coverage factor is partial, since these metrics are limited to exfiltration from IoT devices, resulting in an overall score of Partial.

VPC security groups and network access control lists (NACLs) can limit access to the minimum required ports and therefore protect against adversaries attempting to exfiltrate data using a different protocol than that of the existing command and control channel. In environments where unrestricted Internet access is required, security groups and NACLs can still be used to block known malicious endpoints. Because in such environments the protection is limited to known malicious IP addresses and domains and does not provide protection from such attacks from unknown domains and IP addresses, this is scored as partial coverage resulting in an overall Partial score.

AWS Network Firewall has the ability to pass, drop, or alert on traffic based on the network protocol as well as perform deep packet inspection on the payload. This functionality can be used to block adversaries from accessing resources from which to exfiltrate data as well as prevent resources from communicating with known-bad IP addresses and domains that might be used to receive exfiltrated data. This mapping is given a score of Partial because the known-bad IP addresses and domains would need to be known in advance and AWS Network Firewall wouldn't have deep packet inspection visibility into encrypted non-C2 protocols.