Non-Standard Port

Adversaries may communicate using a protocol and port pairing 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.

Adversaries may also make changes to victim systems to abuse non-standard ports. For example, Registry keys and other configuration settings can be used to modify protocol and port pairings.[3]

ID: T1571
Sub-techniques:  No sub-techniques
Platforms: Linux, Windows, macOS
Version: 1.1
Created: 14 March 2020
Last Modified: 28 February 2023

Procedure Examples

ID Name Description
G0099 APT-C-36

APT-C-36 has used port 4050 for C2 communications.[4]

G0050 APT32

An APT32 backdoor can use HTTP over a non-standard TCP port (e.g 14146) which is specified in the backdoor configuration.[5]

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.[6]

S0239 Bankshot

Bankshot binds and listens on port 1058 for HTTP traffic while also utilizing a FakeTLS method.[7]

S0574 BendyBear

BendyBear has used a custom RC4 and XOR encrypted protocol over port 443 for C2.[8]

C0018 C0018

During C0018, the threat actors opened a variety of ports, including ports 28035, 32467, 41578, and 46892, to establish RDP connections.[9]

C0032 C0032

During the C0032 campaign, TEMP.Veles used port-protocol mismatches on ports such as 443, 4444, 8531, and 50501 during C2.[10]

S0687 Cyclops Blink

Cyclops Blink can use non-standard ports for C2 not typically associated with HTTP or HTTPS traffic.[11]

G0105 DarkVishnya

DarkVishnya used ports 5190 and 7900 for shellcode listeners, and 4444, 4445, 31337 for shellcode C2.[12]

S0021 Derusbi

Derusbi has used unencrypted HTTP on port 443 for C2.[13]

S0367 Emotet

Emotet has used HTTP over ports such as 20, 22, 443, 7080, and 50000, in addition to using ports commonly associated with HTTP/S.[14][15]

G0046 FIN7

FIN7 has used port-protocol mismatches on ports such as 53, 80, 443, and 8080 during C2.[16]

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.[17]

S0237 GravityRAT

GravityRAT has used HTTP over a non-standard port, such as TCP port 46769.[18]


HARDRAIN binds and listens on port 443 with a FakeTLS method.[19]


HOPLIGHT has connected outbound over TCP port 443 with a FakeTLS method.[20]

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.[21][22]

S1016 MacMa

MacMa has used TCP port 5633 for C2 Communication.[23]

G0059 Magic Hound

Magic Hound malware has communicated with its C2 server over TCP ports 4443 and 10151 using HTTP.[24][25]

S0455 Metamorfo

Metamorfo has communicated with hosts over raw TCP on port 9999.[26]

S0149 MoonWind

MoonWind communicates over ports 80, 443, 53, and 8080 via raw sockets instead of the protocols usually associated with the ports.[27]

S0385 njRAT

njRAT has used port 1177 for HTTP C2 communications.[28]

C0014 Operation Wocao

During Operation Wocao, the threat actors used uncommon high ports for its backdoor C2, including ports 25667 and 47000.[29]


OSX_OCEANLOTUS.D has used a custom binary protocol over TCP port 443 for C2.[30]

S1031 PingPull

PingPull can use HTTPS over port 8080 for C2.[31]

S0428 PoetRAT

PoetRAT used TLS to encrypt communications over port 143[32]

S0262 QuasarRAT

QuasarRAT can use port 4782 on the compromised host for TCP callbacks.[33]

S0153 RedLeaves

RedLeaves can use HTTP over non-standard ports, such as 995, for C2.[34]

G0106 Rocke

Rocke's miner connects to a C2 server using port 51640.[35]

S1078 RotaJakiro

RotaJakiro uses a custom binary protocol over TCP port 443.[36]

S0148 RTM

RTM used Port 44443 for its VNC module.[37]

G0034 Sandworm Team

Sandworm Team has used port 6789 to accept connections on the group's SSH server.[38]

S1085 Sardonic

Sardonic has the ability to connect with actor-controlled C2 servers using a custom binary protocol over port 443.[39]

G0091 Silence

Silence has used port 444 when sending data about the system from the client to the server.[40]

S0491 StrongPity

StrongPity has used HTTPS over port 1402 in C2 communication.[41]


SUGARUSH has used port 4585 for a TCP connection to its C2.[42]

S0266 TrickBot

Some TrickBot samples have used HTTP over ports 447 and 8082 for C2.[43][44][45] Newer versions of TrickBot have been known to use a custom communication protocol which sends the data unencrypted over port 443. [46]


TYPEFRAME has used ports 443, 8080, and 8443 with a FakeTLS method.[47]

S0515 WellMail

WellMail has been observed using TCP port 25, without using SMTP, to leverage an open port for secure command and control communications.[48][49]


WIRTE has used HTTPS over ports 2083 and 2087 for C2.[50]

S0412 ZxShell

ZxShell can use ports 1985 and 1986 in HTTP/S communication.[51]


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.


ID Data Source Data Component Detects
DS0029 Network Traffic Network Traffic Content

Analyze packet contents to detect communications that do not follow the expected protocol behavior for the port that is being used.

Network Traffic Flow

Monitor network data flows for unexpected patterns and metadata that may be indicative of a mismatch between protocol and utilized port.


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