T1090.001sub-technique of T1090 Proxy
Internal Proxy
ESXi · Linux · macOS · Network Devices · Windowsnothing on this site yetT1090.001 on attack.mitre.org
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.
how MITRE says to see it
Internal Proxy Behavior via Lateral Host-to-Host C2 Relay
- Anomalous process (e.g., `rundll32`, `svchost`, `cmd`) initiates connections to internal peer hosts not seen in typical communication baselines, used to proxy or forward traffic internally, often using SMB, RPC, or high ports.
- `socat`, `ssh`, `iptables`, or `ncat` invoked from user space or cron jobs to create port forwarding, reverse shells, or inter-host tunnels between compromised Linux systems. Behavior is typically paired with socket activity and high entropy traffic.
- Execution of AppleScript or Automator services launching `ssh -L`, `socat`, or `launchctl` items that dynamically reroute traffic from one Mac endpoint to another. LaunchAgents used to establish permanent internal tunnels.
- ESXi shell execution of tools/scripts (`nc`, `socat`, `perl`) relaying network traffic to other internal hosts, especially when initiated by unauthorized users or VMs.
what reduces it
- 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. Signatures are often for unique indicators within protocols and may be based on the specific C2 protocol used by a particular adversary or tool, and will likely be different across various malware families and versions.