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 | Name | Description | 
|---|---|---|
| G0099 | APT-C-36 | |
| 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] | 
| S0245 | BADCALL | 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 | |
| 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] | 
| S0246 | HARDRAIN | HARDRAIN binds and listens on port 443 with a FakeTLS method.[14] | 
| S0376 | HOPLIGHT | 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 | |
| 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 | |
| S0148 | RTM | |
| 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] Newer versions of TrickBot have been known to use a custom communication protocol which sends the data unencrypted over port 443. [33] | 
| S0263 | TYPEFRAME | TYPEFRAME has used ports 443, 8080, and 8443 with a FakeTLS method.[34] | 
| S0515 | WellMail | WellMail has been observed using TCP port 25, without using SMTP, to leverage an open port for secure command and control communications.[35][36] | 
| 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 | 
|---|---|---|
| DS0029 | Network Traffic | Network Connection Creation | 
| Network Traffic Content | ||
| Network Traffic Flow | 
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.[37]