Adversaries may use an internal proxy to direct command and control traffic between two or more systems in a compromised environment. Many tools exist that enable traffic redirection through proxies or port redirection, including HTRAN, ZXProxy, and ZXPortMap. (Citation: Trend Micro APT Attack Tools) Adversaries use internal proxies to manage command and control communications inside a compromised environment, to reduce the number of simultaneous outbound network connections, to provide resiliency in the face of connection loss, or to ride over existing trusted communications paths between infected systems to avoid suspicion. Internal proxy connections may use common peer-to-peer (p2p) networking protocols, such as SMB, to better blend in with the environment.
By using a compromised internal system as a proxy, adversaries may conceal the true destination of C2 traffic while reducing the need for numerous connections to external systems.
View in MITRE ATT&CK®| Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name | Notes |
|---|---|---|---|---|---|
| CIS-13.8 | Deploy a Network Intrusion Prevention Solution | mitigates | T1090.001 | Internal Proxy |
Comments
Network intrusion prevention solutions can use malware- and protocol-specific signatures to block identifiable internal proxy communications used for adversary command and control.
References
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| CIS-4.8 | Uninstall or Disable Unnecessary Services on Enterprise Assets and Software | mitigates | T1090.001 | Internal Proxy |
Comments
Disabling unnecessary internal proxy listeners, SSH forwarding, port proxies, and routing functions impedes the use of a compromised asset as an internal pivot.
References
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| CIS-4.6 | Securely Manage Enterprise Assets and Software | mitigates | T1090.001 | Internal Proxy |
Comments
Secure SSH configuration can disable unnecessary forwarding and proxy features, reducing the ability to turn a managed asset into a pivot.
References
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| CIS-4.5 | Implement and Manage a Firewall on End-User Devices | mitigates | T1090.001 | Internal Proxy |
Comments
Restricting inbound listeners and lateral outbound connections makes it more difficult for a compromised endpoint to act as an unauthorized proxy for other systems.
References
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