Adversaries may communicate using application layer protocols associated with electronic mail delivery to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.
Protocols such as SMTP/S, POP3/S, and IMAP that carry electronic mail may be very common in environments. Packets produced from these protocols may have many fields and headers in which data can be concealed. Data could also be concealed within the email messages themselves. An adversary may abuse these protocols to communicate with systems under their control within a victim network while also mimicking normal, expected traffic.
View in MITRE ATT&CK®| Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name | Notes |
|---|---|---|---|---|---|
| azure_alerts_for_network_layer | Azure Alerts for Network Layer | technique_scores | T1071.003 | Mail Protocols |
Comments
This control can identify connections to known malicious sites. Scored minimal since the malicious sites must be on a block list.
References
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| cloud_app_security_policies | Cloud App Security Policies | technique_scores | T1071.003 | Mail Protocols |
Comments
This control can identify some evidence of potential C2 via a specific application layer protocol (mail). Relevant alerts include "Suspicious inbox forwarding" and "Suspicious inbox manipulation rule".
References
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| azure_network_traffic_analytics | Azure Network Traffic Analytics | technique_scores | T1071.003 | Mail Protocols |
Comments
This control can detect anomalous application protocol traffic with respect to network security group (NSG) (though web traffic would be typically too commonplace for this control to be useful).
References
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