Sub-technique of T1071 Application Layer Protocol.View on attack.mitre.org
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.
Rules on DetectionCode tagged with T1071.003.
| Rule | Type | Risk | Data source |
|---|---|---|---|
| Windows File Transfer Protocol In Non-Common Process Path | Anomaly | NULL | Sysmon EventID 3 |
| Windows Mail Protocol In Non-Common Process Path | Anomaly | NULL | Sysmon EventID 3 |
| Windows Multi hop Proxy TOR Website Query | Anomaly | NULL | Sysmon EventID 22 |
None recorded.
| Used by | Procedure example |
|---|---|
| GroupAPT28 | APT28 has used IMAP, POP3, and SMTP for a communication channel in various implants, including using self-registered Google Mail accounts and later compromised email servers of its victims. |
| GroupAPT32 | APT32 has used email for C2 via an Office macro. |
| GroupContagious Interview | Contagious Interview has utilized email notifications from malware distribution servers to track victim engagement. |
| GroupKimsuky | Kimsuky has used e-mail to send exfiltrated data to C2 servers. |
| GroupSilverTerrier | SilverTerrier uses SMTP for C2 communications. |
| GroupTurla | Turla has used multiple backdoors which communicate with a C2 server via email attachments. |
| Used by | Procedure example |
|---|---|
| MalwareAgent Tesla | Agent Tesla has used SMTP for C2 communications. |
| MalwareBadPatch | BadPatch uses SMTP for C2. |
| MalwareCannon | Cannon uses SMTP/S and POP3/S for C2 communications by sending and receiving emails. |
| MalwareCHOPSTICK | Various implementations of CHOPSTICK communicate with C2 over SMTP and POP3. |
| MalwareComRAT | ComRAT can use email attachments for command and control. |
| MalwareCORESHELL | CORESHELL can communicate over SMTP and POP3 for C2. |
| MalwareGoopy | Goopy has the ability to use a Microsoft Outlook backdoor macro to communicate with its C2. |
| MalwareIMAPLoader | IMAPLoader uses the IMAP email protocol for command and control purposes. |
Data from MITRE ATT&CK® (Enterprise). ATT&CK® is a registered trademark of The MITRE Corporation.
