LiveActive security incident?Get immediate response
MITRE ATT&CK® Technique

T1095: Non-Application Layer Protocol

Adversaries may use an OSI non-application layer protocol for communication between host and C2 server or among infected hosts within a network. The list of possible protocols is extensive.[1] Specific examples include use of network layer protocols, such as the Internet Control Message Protocol (ICMP), transport layer protocols, such as the User Datagram Protocol (UDP), session layer protocols, such as Socket Secure (SOCKS), as well as redirected/tunneled protocols, such as Serial over LAN (SOL).

ICMP communication between hosts is one example.[2] Because ICMP is part of the Internet Protocol Suite, it is required to be implemented by all IP-compatible hosts.[3] However, it is not as commonly monitored as other Internet Protocols such as TCP or UDP and may be used by adversaries to hide communications.

In ESXi environments, adversaries may leverage the Virtual Machine Communication Interface (VMCI) for communication between guest virtual machines and the ESXi host. This traffic is similar to client-server communications on traditional network sockets but is localized to the physical machine running the ESXi host, meaning it does not traverse external networks (routers, switches). This results in communications that are invisible to external monitoring and standard networking tools like tcpdump, netstat, nmap, and Wireshark. By adding a VMCI backdoor to a compromised ESXi host, adversaries may persistently regain access from any guest VM to the compromised ESXi host’s backdoor, regardless of network segmentation or firewall rules in place.[4]

EnterpriseT1095TechniqueObject v2.4Modified
Glexia's Take · Automated analysis

Security context for executives and security teams

Automation confidenceMedium

T1095: Non-Application Layer Protocol describes Adversaries may use an OSI non-application layer protocol for communication between host and C2 server or among infected hosts within a network. The list of possible protocols is extensive.(Citation: Wikipedia OSI) Specific examples include use of network layer protocols, such as the Internet Control Message Protocol (ICMP), transport layer protocols, such as the User Datagram Protocol (UDP), session layer protocols, such as Socket Secure (SOCKS), as well as redirected/tunneled protocols, such as Serial over LAN (S...

Executive priority

T1095: Non-Application Layer Protocol is an official MITRE ATT&CK technique. Glexia treats it as defensive behavior context for prioritizing monitoring, control validation, and response planning without using the object by itself as an attribution claim.

Technical view

Security teams should validate T1095: Non-Application Layer Protocol by reviewing the official ATT&CK relationships, mapped tactics (command-and-control), supported platforms (ESXi, Linux, macOS, Network Devices), and available local telemetry before making detection or mitigation decisions.

Likely telemetry

  • Official ATT&CK relationships and object metadata
  • Network, endpoint, and security-tool telemetry

Detection direction

  • Validate whether T1095: Non-Application Layer Protocol appears in your detection coverage and tabletop scenarios.
  • Use the object to align executive risk language with SOC, incident response, and detection engineering work.
  • Do not treat ATT&CK relationship context as attribution without corroborating evidence.

Mitigation priorities

  • Map the object to existing controls and identify missing telemetry or response ownership.
  • Prioritize mitigations that reduce exposure on the listed platforms and tactics.
  • Review adjacent ATT&CK relationships before changing policy, detections, or reporting language.
Additional notes and limits

Baseline Glexia take generated from the official MITRE ATT&CK STIX object, source hash, tactics, platforms, and detection fields. It is safe to replace with a richer model-generated take for the same source hash later.

This baseline take is source-grounded and schema-validated, but it does not include environment-specific telemetry, incident evidence, or threat-intelligence corroboration.

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Official MITRE ATT&CK definition

Non-Application Layer Protocol

Adversaries may use an OSI non-application layer protocol for communication between host and C2 server or among infected hosts within a network. The list of possible protocols is extensive.[1] Specific examples include use of network layer protocols, such as the Internet Control Message Protocol (ICMP), transport layer protocols, such as the User Datagram Protocol (UDP), session layer protocols, such as Socket Secure (SOCKS), as well as redirected/tunneled protocols, such as Serial over LAN (SOL).

ICMP communication between hosts is one example.[2] Because ICMP is part of the Internet Protocol Suite, it is required to be implemented by all IP-compatible hosts.[3] However, it is not as commonly monitored as other Internet Protocols such as TCP or UDP and may be used by adversaries to hide communications.

In ESXi environments, adversaries may leverage the Virtual Machine Communication Interface (VMCI) for communication between guest virtual machines and the ESXi host. This traffic is similar to client-server communications on traditional network sockets but is localized to the physical machine running the ESXi host, meaning it does not traverse external networks (routers, switches). This results in communications that are invisible to external monitoring and standard networking tools like tcpdump, netstat, nmap, and Wireshark. By adding a VMCI backdoor to a compromised ESXi host, adversaries may persistently regain access from any guest VM to the compromised ESXi host’s backdoor, regardless of network segmentation or firewall rules in place.[4]

View the same entry on attack.mitre.org (MITRE-hosted reference; in-page links above use the Glexia ATT&CK library.)

Glexia analysis

How security teams should use this page

Treat this object as behavior context, not an attribution claim. Validate the related groups, software, data sources, and mitigations against official ATT&CK relationships and your own telemetry before making control-coverage decisions.

Associated objects

Groups, software, and campaigns

GroupEnterprise

G0022: APT3

APT3 is a China-based threat group that researchers have attributed to China's Ministry of State Security.[1][2] This group is responsible for the campaigns known as Operation Clandestine Fox, Operation Clandestine Wolf, and Operation Double Tap.[1][3] As of June 2015, the group appears to have shifted from targeting primarily US victims to primarily political organizations in Hong Kong.[4]

GroupEnterprise

G0125: HAFNIUM

HAFNIUM is a likely state-sponsored cyber espionage group operating out of China that has been active since at least January 2021. HAFNIUM primarily targets entities in the US across a number of industry sectors, including infectious disease researchers, law firms, higher education institutions, defense contractors, policy think tanks, and NGOs. HAFNIUM has targeted remote management tools and cloud software for intial access and has demonstrated an ability to quickly operationalize exploits for identified vulnerabilities in edge devices.[1][2][3]

GroupEnterprise

G0037: FIN6

FIN6 is a cyber crime group that has stolen payment card data and sold it for profit on underground marketplaces. This group has aggressively targeted and compromised point of sale (PoS) systems in the hospitality and retail sectors.[1][2]

GroupEnterprise

G0047: Gamaredon Group

Gamaredon Group is a suspected Russian cyber espionage group that has targeted military, law enforcement, judiciary, non-profit, and non-governmental organizations in Ukraine since at least 2013. The name Gamaredon Group derives from a misspelling of the word "Armageddon," found in early campaigns.[1][2][3][4][5]

In November 2021, the Ukrainian government publicly attributed Gamaredon Group to Russia’s Federal Security Service (FSB) Center 18, an assessment later supported by multiple independent cybersecurity researchers. [6][5]

GroupEnterprise

G0129: Mustang Panda

Mustang Panda is a China-based cyber espionage threat actor that has been conducting operations since at least 2012. Mustang Panda has been known to use tailored phishing lures and decoy documents to deliver malicious payloads. Mustang Panda has targeted government, diplomatic, and non-governmental organizations, including think tanks, religious institutions, and research entities, across the United States, Europe, and Asia, with notable activity in Russia, Mongolia, Myanmar, Pakistan, and Vietnam. [1][2][3][4][5][6][7][8][9][10][11][12][13]

GroupEnterprise

G1048: UNC3886

UNC3886 is a China-nexus cyberespionage group that has been active since at least 2022, targeting defense, technology, and telecommunication organizations located in the United States and the Asia-Pacific-Japan (APJ) regions. UNC3886 has displayed a deep understanding of edge devices and virtualization technologies through the exploitation of zero-day vulnerabilities and the use of novel malware families and utilities.[1][2]

GroupEnterprise

G1002: BITTER

BITTER is a suspected South Asian cyber espionage threat group that has been active since at least 2013. BITTER has targeted government, energy, and engineering organizations in Pakistan, China, Bangladesh, and Saudi Arabia.[1][2]

GroupEnterprise

G1003: Ember Bear

Ember Bear is a Russian state-sponsored cyber espionage group that has been active since at least 2020, linked to Russia's General Staff Main Intelligence Directorate (GRU) 161st Specialist Training Center (Unit 29155).[1] Ember Bear has primarily focused operations against Ukrainian government and telecommunication entities, but has also operated against critical infrastructure entities in Europe and the Americas.[2] Ember Bear conducted the WhisperGate destructive wiper attacks against Ukraine in early 2022.[3][4][1] There is some confusion as to whether Ember Bear overlaps with another Russian-linked entity referred to as Saint Bear. At present available evidence strongly suggests these are distinct activities with different behavioral profiles.[2][5]

GroupEnterprise

G1022: ToddyCat

ToddyCat is a sophisticated threat group that has been active since at least 2020 using custom loaders and malware in multi-stage infection chains against government and military targets across Europe and Asia.[1][2]

GroupEnterprise

G1013: Metador

Metador is a suspected cyber espionage group that was first reported in September 2022. Metador has targeted a limited number of telecommunication companies, internet service providers, and universities in the Middle East and Africa. Security researchers named the group Metador based on the "I am meta" string in one of the group's malware samples and the expectation of Spanish-language responses from C2 servers.[1]

GroupEnterprise

G0068: PLATINUM

PLATINUM is an activity group that has targeted victims since at least 2009. The group has focused on targets associated with governments and related organizations in South and Southeast Asia. [1]

MalwareEnterprise

S1204: cd00r

cd00r is an open-source backdoor for UNIX and UNIX-variant operating systems that was orginally released in 2000. cd00r source code is primarily based on a packet-capturing program as it utilizes a sniffer to listen for specific sequences of network traffic or "secret knock" before executing the attacker's code.[1][2]

Network Devices
MalwareEnterprise

S1100: Ninja

Ninja is a malware developed in C++ that has been used by ToddyCat to penetrate networks and control remote systems since at least 2020. Ninja is possibly part of a post exploitation toolkit exclusively used by ToddyCat and allows multiple operators to work simultaneously on the same machine. Ninja has been used against government and military entities in Europe and Asia and observed in specific infection chains being deployed by Samurai.[1]

Windows
MalwareEnterprise

S1078: RotaJakiro

RotaJakiro is a 64-bit Linux backdoor used by APT32. First seen in 2018, it uses a plugin architecture to extend capabilities. RotaJakiro can determine it's permission level and execute according to access type (`root` or `user`).[1][2]

Linux
MalwareEnterprise

S1105: COATHANGER

COATHANGER is a remote access tool (RAT) targeting FortiGate networking appliances. First used in 2023 in targeted intrusions against military and government entities in the Netherlands along with other victims, COATHANGER was disclosed in early 2024, with a high confidence assessment linking this malware to a state-sponsored entity in the People's Republic of China. COATHANGER is delivered after gaining access to a FortiGate device, with in-the-wild observations linked to exploitation of CVE-2022-42475. The name COATHANGER is based on a unique string in the malware used to encrypt configuration files on disk: “She took his coat and hung it up”.[1]

LinuxNetwork Devices
MalwareEnterprise

S1085: Sardonic

Sardonic is a backdoor written in C and C++ that is known to be used by FIN8, as early as August 2021 to target a financial institution in the United States. Sardonic has a plugin system that can load specially made DLLs and execute their functions.[1][2]

Windows
MalwareEnterprise

S1187: reGeorg

reGeorg is an open-source web shell written in Python that can be used as a proxy to bypass firewall rules and tunnel data in and out of targeted networks.[1][2]

Network DevicesWindowsmacOS
MalwareEnterprise

S0043: BUBBLEWRAP

BUBBLEWRAP is a full-featured, second-stage backdoor used by the admin@338 group. It is set to run when the system boots and includes functionality to check, upload, and register plug-ins that can further enhance its capabilities. [1]

Windows
MalwareEnterprise

S1245: InvisibleFerret

InvisibleFerret is a modular python malware that is leveraged for data exfiltration and remote access capabilities.[1][2][3] InvisibleFerret consists of four modules: main, payload, browser, and AnyDesk.[1] InvisibleFerret malware has been leveraged by North Korea-affiliated threat actors identified as DeceptiveDevelopment or Contagious Interview since 2023.[4][2][3][5] InvisibleFerret has historically been introduced to the victim environment through the use of the BeaverTail malware.[6][1][2][3][5]

LinuxmacOSWindows
CampaignEnterprise

C0035: KV Botnet Activity

KV Botnet Activity consisted of exploitation of primarily “end-of-life” small office-home office (SOHO) equipment from manufacturers such as Cisco, NETGEAR, and DrayTek. KV Botnet Activity was used by Volt Typhoon to obfuscate connectivity to victims in multiple critical infrastructure segments, including energy and telecommunication companies and entities based on the US territory of Guam. While the KV Botnet is the most prominent element of this campaign, it overlaps with another botnet cluster referred to as the JDY cluster.[1] This botnet was disrupted by US law enforcement entities in early 2024 after periods of activity from October 2022 through January 2024.[2]

CampaignEnterprise

C0056: RedPenguin

The RedPenguin project was launched by Juniper in July 2024 to investigate reported malware infections of Juniper MX Series routers. RedPenguin activity was separately attributed to UNC3886 and included the deployment of multiple custom versions of the publicly-available TINYSHELL backdoor on Juniper routers.[1][2]

CampaignEnterprise

C0029: Cutting Edge

Cutting Edge was a campaign conducted by suspected China-nexus espionage actors, variously identified as UNC5221/UTA0178 and UNC5325, that began as early as December 2023 with the exploitation of zero-day vulnerabilities in Ivanti Connect Secure (previously Pulse Secure) VPN appliances. Cutting Edge targeted the U.S. defense industrial base and multiple sectors globally including telecommunications, financial, aerospace, and technology. Cutting Edge featured the use of defense evasion and living-off-the-land (LoTL) techniques along with the deployment of web shells and other custom malware.[1][2][3][4][5]

CampaignEnterprise

C0021: C0021

C0021 was a spearphishing campaign conducted in November 2018 that targeted public sector institutions, non-governmental organizations (NGOs), educational institutions, and private-sector corporations in the oil and gas, chemical, and hospitality industries. The majority of targets were located in the US, particularly in and around Washington D.C., with other targets located in Europe, Hong Kong, India, and Canada. C0021's technical artifacts, tactics, techniques, and procedures (TTPs), and targeting overlap with previous suspected APT29 activity.[1][2]

CampaignEnterprise

C0039: Versa Director Zero Day Exploitation

Versa Director Zero Day Exploitation was conducted by Volt Typhoon from early June through August 2024 as zero-day exploitation of Versa Director servers controlling software-defined wide area network (SD-WAN) applications. Since tracked as CVE-2024-39717, exploitation focused on credential capture from compromised Versa Director servers at managed service providers (MSPs) and internet service providers (ISPs) to enable follow-on access to service provider clients. Versa Director Zero Day Exploitation was followed by the delivery of the VersaMem web shell for both credential theft and follow-on code execution.[1]

CampaignEnterprise

C0014: Operation Wocao

Operation Wocao was a cyber espionage campaign that targeted organizations around the world, including in Brazil, China, France, Germany, Italy, Mexico, Portugal, Spain, the United Kingdom, and the United States. The suspected China-based actors compromised government organizations and managed service providers, as well as aviation, construction, energy, finance, health care, insurance, offshore engineering, software development, and transportation companies.[1]

Security researchers assessed the Operation Wocao actors used similar TTPs and tools as APT20, suggesting a possible overlap. Operation Wocao was named after an observed command line entry by one of the threat actors, possibly out of frustration from losing webshell access.[1]

Relationship explorer

All related ATT&CK context

Mitigations

Mitigation direction

Change history

Object version and sync metadata

The fields below describe the current mirrored snapshot. When Glexia retains multiple ATT&CK source imports, you can open the table to compare the same object across releases (hashes and MITRE timestamps). For MITRE’s own release notes and roadmap, see ATT&CK resources — Updates.

ATT&CK release
19.2
Object version
2.4
Created
Modified
Raw hash
b0e542b748101267...
Imported snapshots across ATT&CK releases(2)
ReleaseBundle importedObject versionModifiedStatusRaw hash
19.22.4Current bundleb0e542b74810…
19.12.4Older bundleb0e542b74810…
Raw source

Mirrored ATT&CK source object

The raw object is retained through the mirrored ATT&CK source bundle and object hash. The raw endpoint returns the exact object from the mirrored bundle when available.

Source references

External references and citations

MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.

  1. [1]
    Wikipedia OSI

    Wikipedia. (n.d.). List of network protocols (OSI model). Retrieved December 4, 2014.

  2. [2]
    Cisco Synful Knock Evolution

    Graham Holmes. (2015, October 8). Evolution of attacks on Cisco IOS devices. Retrieved October 19, 2020.

    Open source URL
  3. [3]
    Microsoft ICMP

    Microsoft. (n.d.). Internet Control Message Protocol (ICMP) Basics. Retrieved December 1, 2014.

  4. [4]
    Google Cloud Threat Intelligence VMWare ESXi Zero-Day 2023

    Alexander Marvi, Brad Slaybaugh, Ron Craft, and Rufus Brown. (2023, June 13). VMware ESXi Zero-Day Used by Chinese Espionage Actor to Perform Privileged Guest Operations on Compromised Hypervisors. Retrieved March 26, 2025.

    Open source URL
  5. [5]
    Cisco Blog Legacy Device Attacks

    Omar Santos. (2020, October 19). Attackers Continue to Target Legacy Devices. Retrieved October 20, 2020.

    Open source URL
  6. [6]
    University of Birmingham C2

    Gardiner, J., Cova, M., Nagaraja, S. (2014, February). Command & Control Understanding, Denying and Detecting. Retrieved April 20, 2016.

    Open source URL
  7. [7]
    mitre-attackT1095
    Open source URL
Source and licensing

Source: MITRE ATT&CK®. © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. MITRE ATT&CK and ATT&CK are registered trademarks of The MITRE Corporation. Glexia is not affiliated with or endorsed by MITRE.