Proxy
Where this stands
One published detection covers this technique. Every one is unverified — no rule on Siemphony has been executed against real telemetry.
What the technique is
Adversaries may use a connection proxy to direct network traffic between systems or act as an intermediary for network communications to a command and control server to avoid direct connections to their infrastructure. Many tools exist that enable traffic redirection through proxies or port redirection, including HTRAN, ZXProxy, and ZXPortMap. Adversaries use these types of proxies to manage command and control communications, reduce the number of simultaneous outbound network connections, provide resiliency in the face of connection loss, or to ride over existing trusted communications paths between victims to avoid suspicion. Adversaries may chain together multiple proxies to further disguise the source of malicious traffic. Adversaries can also take advantage of routing schemes in Content Delivery Networks (CDNs) to proxy command and control traffic.
Read it on attack.mitre.orgWhat MITRE says you would watch
- AN1229
Suspicious process spawning (e.g., rundll32, svchost, powershell, or netsh) followed by network connection creation to internal hosts or uncommon external endpoints on high or non-standard ports.
- AN1230
User-space tools (e.g., socat, ncat, iptables, ssh) used in non-standard ways to establish reverse shells, port-forwarding, or inter-host connections. Often chained with uncommon outbound destinations or SSH tunnels.
- AN1231
AppleScript, LaunchAgents, or remote login services (ssh, networksetup) establishing proxy tunnels or dynamic port forwards to external IPs or alternate local hosts.
Technique names and descriptions © MITRE ATT&CK®, CC BY 4.0. Not endorsed by MITRE.