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]
Security context for executives and security teams
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.
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]
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.
Groups, software, and campaigns
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]
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]
G0037: FIN6
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]
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]
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]
G1002: BITTER
G0135: BackdoorDiplomacy
BackdoorDiplomacy is a cyber espionage threat group that has been active since at least 2017. BackdoorDiplomacy has targeted Ministries of Foreign Affairs and telecommunication companies in Africa, Europe, the Middle East, and Asia.[1]
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]
G1022: ToddyCat
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]
G0068: PLATINUM
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]
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]
S0662: RCSession
RCSession is a backdoor written in C++ that has been in use since at least 2018 by Mustang Panda and by Threat Group-3390 (Type II Backdoor).[1][2][3]
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]
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]
S1085: Sardonic
S0083: Misdat
Misdat is a backdoor that was used in Operation Dust Storm from 2010 to 2011.[1]
S1187: reGeorg
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]
S1121: LITTLELAMB.WOOLTEA
LITTLELAMB.WOOLTEA is a backdoor that was used by UNC5325 during Cutting Edge to deploy malware on targeted Ivanti Connect Secure VPNs and to establish persistence across system upgrades and patches.[1]
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]
S0630: Nebulae
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]
C0047: RedDelta Modified PlugX Infection Chain Operations
RedDelta Modified PlugX Infection Chain Operations was executed by Mustang Panda from mid-2023 through the end of 2024 against multiple entities in East and Southeast Asia. RedDelta Modified PlugX Infection Chain Operations involved phishing to deliver malicious files or links to users prompting follow-on installer downloads to load PlugX on victim machines in a persistent state.[1]
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]
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]
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]
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]
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]
C0034: 2022 Ukraine Electric Power Attack
The 2022 Ukraine Electric Power Attack was a Sandworm Team campaign that used a combination of GOGETTER, Neo-REGEORG, CaddyWiper, and living of the land (LotL) techniques to gain access to a Ukrainian electric utility to send unauthorized commands from their SCADA system.[1][2]
All related ATT&CK context
Mitigation direction
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.
Imported snapshots across ATT&CK releases(2)
| Release | Bundle imported | Object version | Modified | Status | Raw hash |
|---|---|---|---|---|---|
| 19.2 | 2.4 | Current bundle | b0e542b74810… | ||
| 19.1 | 2.4 | Older bundle | b0e542b74810… |
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.
External references and citations
MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.
- [1]Wikipedia OSI
Wikipedia. (n.d.). List of network protocols (OSI model). Retrieved December 4, 2014.
- [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]Microsoft ICMP
Microsoft. (n.d.). Internet Control Message Protocol (ICMP) Basics. Retrieved December 1, 2014.
- [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]Cisco Blog Legacy Device Attacks
Omar Santos. (2020, October 19). Attackers Continue to Target Legacy Devices. Retrieved October 20, 2020.
Open source URL - [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]mitre-attackT1095Open source URL
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