t1090-001-internal-proxy

name	T1090.001_internal-proxy
description	Adversaries may use an internal proxy to direct command and control traffic between two or more systems in a compromised environment.
category	configuration
version	18.1
author	cyberstrike-official
tags	["mitre-attack","enterprise","t1090.001","command-and-control","linux","network-devices","windows","macos","esxi","sub-technique"]
technique_id	T1090.001
tactic	command-and-control
all_tactics	["command-and-control"]
platforms	["Linux","Network Devices","Windows","macOS","ESXi"]
mitre_url	https://attack.mitre.org/techniques/T1090/001
tech_stack	["linux","network devices","windows","macos","esxi"]
cwe_ids	["CWE-300"]
chains_with	["T1090","T1090.002","T1090.003","T1090.004"]
prerequisites	["T1090"]
severity_boost	{"T1090":"Chain with T1090 for deeper attack path","T1090.002":"Chain with T1090.002 for deeper attack path","T1090.003":"Chain with T1090.003 for deeper attack path"}

T1090.001 Internal Proxy

Sub-technique of: T1090

High-Level Description

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. 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.

Kill Chain Phase

• Command and Control (TA0011)

Platforms: Linux, Network Devices, Windows, macOS, ESXi

What to Check

• Identify if Internal Proxy technique is applicable to target environment
• Check Linux systems for indicators of Internal Proxy
• Check Network Devices systems for indicators of Internal Proxy
• Check Windows systems for indicators of Internal Proxy
• Verify mitigations are bypassed or absent (1 known mitigations)
• Assess detection coverage (1 detection strategies)

How to Test

Atomic Red Team Tests

The following tests are from Atomic Red Team and provide actionable ways to test this technique:

Atomic Test 1: Connection Proxy

Enable traffic redirection.

Note that this test may conflict with pre-existing system configuration.

Supported Platforms: linux, macos

export #{proxy_scheme}_proxy=#{proxy_server}:#{proxy_port}
curl #{test_url}

Dependencies: