Technique on mitre.org

T1102.002: Bidirectional Communication

Adversaries may use an existing, legitimate external Web service as a means for sending commands to and receiving output from a compromised system over the Web service channel. Compromised systems may leverage popular websites and social media to host command and control (C2) instructions. Those infected systems can then send the output from those commands back over that Web service channel. The return traffic may occur in a variety of ways, depending on the Web service being utilized. For example, the return traffic may take the form of the compromised system posting a comment on a forum, issuing a pull request to development project, updating a document hosted on a Web service, or by sending a Tweet.

Popular websites and social media acting as a mechanism for C2 may give a significant amount of cover due to the likelihood that hosts within a network are already communicating with them prior to a compromise. Using common services, such as those offered by Google or Twitter, makes it easier for adversaries to hide in expected noise. Web service providers commonly use SSL/TLS encryption, giving adversaries an added level of protection.

Positive Technologies products that cover the technique

MaxPatrol SIEM knowledge base

supply_chain: PT-CR-1963: SupplyChain_TeamCity_Execution_Via_Request: The ability to remotely execute commands was enabled, and the code was executed. After receiving a TeamCity API access token, attackers can enable the rest.debug.processes.enable option which allows them to run commands on the server via POST requests dnsmasq: PT-CR-2201: Dnsmasq_Telegram_Bot_API_Request_Detection: Suspicious DNS requests to api.telegram.org used by any type of Telegram bots mitre_attck_command_and_control: PT-CR-2413: Connect_Suspicious_File_To_API_Telegram: Suspicious connection of a file to the api.telegram.org service bind: PT-CR-2186: BIND_Telegram_Bot_API_Request_Detection: A request for DNS parameters for a Telegram API resource. Attackers send such requests to execute commands and ultimately compromise the system.

Detection

ID	DS0029	Data source and component	Network Traffic: Network Traffic Content	Description	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).

ID	DS0029	Data source and component	Network Traffic: Network Connection Creation	Description	Monitor for newly constructed network connections that are sent or received by untrusted hosts.

ID	DS0029	Data source and component	Network Traffic: Network Traffic Flow	Description	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.

ID	Data source and component	Description
DS0029	Network Traffic: Network Traffic Content	Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
DS0029	Network Traffic: Network Connection Creation	Monitor for newly constructed network connections that are sent or received by untrusted hosts.
DS0029	Network Traffic: Network Traffic Flow	Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.

Mitigation

ID	M1021	Name	Restrict Web-Based Content	Description	Web proxies can be used to enforce external network communication policy that prevents use of unauthorized external services.

ID	M1031	Name	Network Intrusion Prevention	Description	Network intrusion detection and prevention systems that use network signatures to identify traffic for specific adversary malware can be used to mitigate activity at the network level.

ID	Name	Description
M1021	Restrict Web-Based Content	Web proxies can be used to enforce external network communication policy that prevents use of unauthorized external services.
M1031	Network Intrusion Prevention	Network intrusion detection and prevention systems that use network signatures to identify traffic for specific adversary malware can be used to mitigate activity at the network level.