Non-Standard Port

Adversaries may communicate using a protocol and port paring that are typically not associated. For example, HTTPS over port 8088[1] or port 587[2] as opposed to the traditional port 443. Adversaries may make changes to the standard port used by a protocol to bypass filtering or muddle analysis/parsing of network data.

ID: T1571
Sub-techniques:  No sub-techniques
Platforms: Linux, Windows, macOS
Data Sources: Network Traffic: Network Connection Creation, Network Traffic: Network Traffic Content, Network Traffic: Network Traffic Flow
Version: 1.0
Created: 14 March 2020
Last Modified: 26 March 2020

Procedure Examples

ID Name Description
G0099 APT-C-36

APT-C-36 has used port 4050 for C2 communications.[3]

G0050 APT32

An APT32 backdoor can use HTTP over a non-standard TCP port (e.g 14146) which is specified in the backdoor configuration.[4]

G0064 APT33

APT33 has used HTTP over TCP ports 808 and 880 for command and control.[1]


BADCALL communicates on ports 443 and 8000 with a FakeTLS method.[5]

S0239 Bankshot

Bankshot binds and listens on port 1058 for HTTP traffic while also utilizing a FakeTLS method.[6]

S0574 BendyBear

BendyBear has used a custom RC4 and XOR encrypted protocol over port 443 for C2.[7]

G0105 DarkVishnya

DarkVishnya used ports 5190 and 7900 for shellcode listeners, and 4444, 4445, 31337 for shellcode C2.[8]

S0021 Derusbi

Derusbi has used unencrypted HTTP on port 443 for C2.[9]

S0367 Emotet

Emotet has used HTTP over ports such as 20, 22, 7080, and 50000, in addition to using ports commonly associated with HTTP/S.[10]

G0046 FIN7

FIN7 has used port-protocol mismatches on ports such as 53, 80, 443, and 8080 during C2.[11]

S0493 GoldenSpy

GoldenSpy has used HTTP over ports 9005 and 9006 for network traffic, 9002 for C2 requests, 33666 as a WebSocket, and 8090 to download files.[12]

S0237 GravityRAT

GravityRAT has used HTTP over a non-standard port, such as TCP port 46769.[13]


HARDRAIN binds and listens on port 443 with a FakeTLS method.[14]


HOPLIGHT has connected outbound over TCP port 443 with a FakeTLS method.[15]

G0032 Lazarus Group

Some Lazarus Group malware uses a list of ordered port numbers to choose a port for C2 traffic, creating port-protocol mismatches.[16][17]

G0059 Magic Hound

Magic Hound malware has communicated with its C2 server over TCP port 4443 using HTTP.[18]

S0455 Metamorfo

Metamorfo has communicated with hosts over raw TCP on port 9999.[19]

S0149 MoonWind

MoonWind communicates over ports 80, 443, 53, and 8080 via raw sockets instead of the protocols usually associated with the ports.[20]

S0385 njRAT

njRAT has used port 1177 for HTTP C2 communications.[21]

S0428 PoetRAT

PoetRAT used TLS to encrypt communications over port 143[22]

S0153 RedLeaves

RedLeaves can use HTTP over non-standard ports, such as 995, for C2.[23]

G0106 Rocke

Rocke's miner connects to a C2 server using port 51640.[24]

S0148 RTM

RTM used Port 44443 for its VNC module.[25]

G0034 Sandworm Team

Sandworm Team has used port 6789 to accept connections on the group's SSH server.[26]

G0091 Silence

Silence has used port 444 when sending data about the system from the client to the server.[27]

S0491 StrongPity

StrongPity has used HTTPS over port 1402 in C2 communication.[28]

G0088 TEMP.Veles

TEMP.Veles has used port-protocol mismatches on ports such as 443, 4444, 8531, and 50501 during C2.[29]

S0266 TrickBot

Some TrickBot samples have used HTTP over ports 447 and 8082 for C2.[30][31][32]


TYPEFRAME has used ports 443, 8080, and 8443 with a FakeTLS method.[33]

S0515 WellMail

WellMail has been observed using TCP port 25, without using SMTP, to leverage an open port for secure command and control communications.[34][35]


ID Mitigation Description
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.

M1030 Network Segmentation

Properly configure firewalls and proxies to limit outgoing traffic to only necessary ports for that particular network segment.


Analyze packet contents to detect communications that do not follow the expected protocol behavior for the port that is being used. Analyze network data for uncommon data flows (e.g., a client sending significantly more data than it receives from a server). Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.[36]


  1. Security Response attack Investigation Team. (2019, March 27). Elfin: Relentless Espionage Group Targets Multiple Organizations in Saudi Arabia and U.S.. Retrieved April 10, 2019.
  2. Zhang, X. (2018, April 05). Analysis of New Agent Tesla Spyware Variant. Retrieved November 5, 2018.
  3. QiAnXin Threat Intelligence Center. (2019, February 18). APT-C-36: Continuous Attacks Targeting Colombian Government Institutions and Corporations. Retrieved May 5, 2020.
  4. Dumont, R. (2019, March 20). Fake or Fake: Keeping up with OceanLotus decoys. Retrieved April 1, 2019.
  5. US-CERT. (2018, February 06). Malware Analysis Report (MAR) - 10135536-G. Retrieved June 7, 2018.
  6. US-CERT. (2017, December 13). Malware Analysis Report (MAR) - 10135536-B. Retrieved July 17, 2018.
  7. Harbison, M. (2021, February 9). BendyBear: Novel Chinese Shellcode Linked With Cyber Espionage Group BlackTech. Retrieved February 16, 2021.
  8. Golovanov, S. (2018, December 6). DarkVishnya: Banks attacked through direct connection to local network. Retrieved May 15, 2020.
  9. Fidelis Cybersecurity. (2016, February 29). The Turbo Campaign, Featuring Derusbi for 64-bit Linux. Retrieved March 2, 2016.
  10. Brumaghin, E.. (2019, January 15). Emotet re-emerges after the holidays. Retrieved March 25, 2019.
  11. Carr, N., et al. (2018, August 01). On the Hunt for FIN7: Pursuing an Enigmatic and Evasive Global Criminal Operation. Retrieved August 23, 2018.
  12. Trustwave SpiderLabs. (2020, June 25). The Golden Tax Department and Emergence of GoldenSpy Malware. Retrieved July 23, 2020.
  13. Mercer, W., Rascagneres, P. (2018, April 26). GravityRAT - The Two-Year Evolution Of An APT Targeting India. Retrieved May 16, 2018.
  14. US-CERT. (2018, February 05). Malware Analysis Report (MAR) - 10135536-F. Retrieved June 11, 2018.
  15. US-CERT. (2019, April 10). MAR-10135536-8 – North Korean Trojan: HOPLIGHT. Retrieved April 19, 2019.
  16. Novetta Threat Research Group. (2016, February 24). Operation Blockbuster: Unraveling the Long Thread of the Sony Attack. Retrieved February 25, 2016.
  17. Novetta Threat Research Group. (2016, February 24). Operation Blockbuster: Remote Administration Tools & Content Staging Malware Report. Retrieved March 16, 2016.
  18. Lee, B. and Falcone, R. (2017, February 15). Magic Hound Campaign Attacks Saudi Targets. Retrieved December 27, 2017.
  1. Sierra, E., Iglesias, G.. (2018, April 24). Metamorfo Campaigns Targeting Brazilian Users. Retrieved July 30, 2020.
  2. Miller-Osborn, J. and Grunzweig, J.. (2017, March 30). Trochilus and New MoonWind RATs Used In Attack Against Thai Organizations. Retrieved March 30, 2017.
  3. Pascual, C. (2018, November 27). AutoIt-Compiled Worm Affecting Removable Media Delivers Fileless Version of BLADABINDI/njRAT Backdoor. Retrieved June 4, 2019.
  4. Mercer, W, et al. (2020, April 16). PoetRAT: Python RAT uses COVID-19 lures to target Azerbaijan public and private sectors. Retrieved April 27, 2020.
  5. PwC and BAE Systems. (2017, April). Operation Cloud Hopper: Technical Annex. Retrieved April 13, 2017.
  6. Anomali Labs. (2019, March 15). Rocke Evolves Its Arsenal With a New Malware Family Written in Golang. Retrieved April 24, 2019.
  7. Faou, M. and Boutin, J. (2017, February). Read The Manual: A Guide to the RTM Banking Trojan. Retrieved March 9, 2017.
  8. Cherepanov, A.. (2016, January 3). BlackEnergy by the SSHBearDoor: attacks against Ukrainian news media and electric industry . Retrieved June 10, 2020.
  9. Group-IB. (2018, September). Silence: Moving Into the Darkside. Retrieved May 5, 2020.
  10. Tudorica, R. et al. (2020, June 30). StrongPity APT - Revealing Trojanized Tools, Working Hours and Infrastructure. Retrieved July 20, 2020.
  11. Miller, S, et al. (2019, April 10). TRITON Actor TTP Profile, Custom Attack Tools, Detections, and ATT&CK Mapping. Retrieved April 16, 2019.
  12. Salinas, M., Holguin, J. (2017, June). Evolution of Trickbot. Retrieved July 31, 2018.
  13. Reaves, J. (2016, October 15). TrickBot: We Missed you, Dyre. Retrieved August 2, 2018.
  14. Antazo, F. (2016, October 31). TSPY_TRICKLOAD.N. Retrieved September 14, 2018.
  15. US-CERT. (2018, June 14). MAR-10135536-12 – North Korean Trojan: TYPEFRAME. Retrieved July 13, 2018.
  16. CISA. (2020, July 16). MAR-10296782-3.v1 – WELLMAIL. Retrieved September 29, 2020.
  17. National Cyber Security Centre. (2020, July 16). Advisory: APT29 targets COVID-19 vaccine development. Retrieved September 29, 2020.
  18. Gardiner, J., Cova, M., Nagaraja, S. (2014, February). Command & Control Understanding, Denying and Detecting. Retrieved April 20, 2016.