T1571: Non-Standard Port

Framework: MITRE ATT&CK · Tactic: Command and Control · Total Cataloged Families: 5 · Observed Samples: 5,339 · Primary Threat Categories: Rat · Infostealer · Advanced Threat

Operational Executive Summary

T1571 (Non-Standard Port) is classified under the Command and Control tactic within the MITRE ATT&CK framework. Communication channels and covert protocols utilized to maintain interactive control of compromised implants through legitimate web protocols, encrypted proxies, and DNS tunneling. In telemetry gathered across enterprise endpoints and the EMBER 2018 benchmark, this technique was weaponized across 5 distinct malware families, totaling over 5,339 validated samples.

Technical Anatomy & Adversary Tradecraft

Adversaries leverage Non-Standard Port to accomplish operational objectives while minimizing anomalous forensic footprints. When executing Non-Standard Port, malicious binaries commonly interact directly with low-level Windows APIs, kernel mode drivers, or native scripting interfaces to bypass traditional file-integrity monitors and static antivirus signatures.

In modern multi-stage campaigns, T1571 is frequently observed functioning as an intermediate bridge: initial access payloads (such as spearphishing loaders or exploit macros) execute Non-Standard Port to establish in-memory execution or persistence before staging secondary ransomware or data-exfiltration implants.

Authoritative MITRE ATT&CK Reference: View official technique documentation, sub-techniques, and adversary groups at https://attack.mitre.org/techniques/T1571/.

Detection Engineering & Threat Hunting

Detecting Non-Standard Port requires telemetry correlation across endpoint detection and response (EDR) agents, Sysmon event streams, and security information event management (SIEM) pipelines:

Process Creation & Lineage: Monitor parent-child process anomalies where unexpected parent binaries (e.g., Office executables, web browsers, or script hosts) spawn command shells or native Windows utilities.
API Hooking & Behavioral Telemetry: EDR platforms should flag rapid calls to memory allocation, process injection, or registry manipulation APIs originating from unbacked executable memory regions.
Network Anomaly Correlation: Cross-reference endpoint execution timestamps with external network socket establishment to identify anomalous beaconing or covert data staging.

SOC Containment & Hardening Guidance

To mitigate risks associated with T1571 (Non-Standard Port) across production infrastructure, security teams should implement the following defensive controls:

Attack Surface Reduction (ASR): Enforce strict application control policies (WDAC or AppLocker) to restrict execution to signed and verified corporate binaries.
Least Privilege & Credential Hygiene: Restrict local administrative privileges to prevent adversaries from tampering with defensive agents or escalating privileges.
Network Microsegmentation: Restrict lateral communication across endpoint VLANs to prevent wormable payloads from utilizing Non-Standard Port across adjacent network segments.

→ Incident Response Guidance: Read our Botnet Protection & Remediation

Cataloged Malware Families Utilizing T1571 (5 Families)

The following malware families in the SystemHelpDesk catalog have been verified utilizing T1571 (Non-Standard Port):

5 families

Family	Category	Sample Count	Technical Summary
bladabindi	Rat	`3,930`	Bladabindi (universally recognized in the cybersecurity community as njRAT) is an infamous, widely proliferated remote access trojan originally authored by an i...
msilperseus	Infostealer	`596`	MSIL/Perseus (identified in endpoint telemetry as Trojan:MSIL/Perseus, Trojan.MSIL.Perseus, and MSIL/Perseus.A) is a modular .NET-based information stealer and ...
snake	Advanced Threat	`450`	Snake (also tracked across intelligence agencies and vendors as Turla, Uroburos, Ouroboros, and Snake Rootkit) is an exceptionally sophisticated cyber espionage...
farfli	Rat	`360`	Trojan:Win32/Farfli is a sophisticated Remote Access Trojan (RAT) derived from the leaked Gh0st RAT codebase, customized extensively by Chinese state-sponsored ...
tftpd	Ransomware	`3`	HackTool:Win32/Tftpd is a critical detection that flags the presence of an unauthorized Trivial File Transfer Protocol (TFTP) daemon (server) running on a Windo...