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MITRE ATT&CK® Technique

T1033: System Owner/User Discovery

Adversaries may attempt to identify the primary user, currently logged in user, set of users that commonly uses a system, or whether a user is actively using the system. They may do this, for example, by retrieving account usernames or by using OS Credential Dumping. The information may be collected in a number of different ways using other Discovery techniques, because user and username details are prevalent throughout a system and include running process ownership, file/directory ownership, session information, and system logs. Adversaries may use the information from System Owner/User Discovery during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.

Various utilities and commands may acquire this information, including whoami. In macOS and Linux, the currently logged in user can be identified with w and who. On macOS the dscl . list /Users | grep -v '_' command can also be used to enumerate user accounts. Environment variables, such as %USERNAME% and $USER, may also be used to access this information.

On network devices, Network Device CLI commands such as `show users` and `show ssh` can be used to display users currently logged into the device.[1][2]

EnterpriseT1033TechniqueObject v1.6Modified
Glexia's Take · Automated analysis

Security context for executives and security teams

Automation confidenceMedium

T1033: System Owner/User Discovery describes Adversaries may attempt to identify the primary user, currently logged in user, set of users that commonly uses a system, or whether a user is actively using the system. They may do this, for example, by retrieving account usernames or by using [OS Credential Dumping](https://attack.mitre.org/techniques/T1003). The information may be collected in a number of different ways using other Discovery techniques, because user and username details are prevalent throughout a system and include running process ownership, fil...

Executive priority

T1033: System Owner/User Discovery 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 T1033: System Owner/User Discovery by reviewing the official ATT&CK relationships, mapped tactics (discovery), supported platforms (Linux, macOS, Network Devices, Windows), and available local telemetry before making detection or mitigation decisions.

Likely telemetry

  • Official ATT&CK relationships and object metadata
  • Endpoint process, command-line, and script execution logs
  • Network, endpoint, and security-tool telemetry

Detection direction

  • Validate whether T1033: System Owner/User Discovery 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

System Owner/User Discovery

Adversaries may attempt to identify the primary user, currently logged in user, set of users that commonly uses a system, or whether a user is actively using the system. They may do this, for example, by retrieving account usernames or by using OS Credential Dumping. The information may be collected in a number of different ways using other Discovery techniques, because user and username details are prevalent throughout a system and include running process ownership, file/directory ownership, session information, and system logs. Adversaries may use the information from System Owner/User Discovery during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.

Various utilities and commands may acquire this information, including whoami. In macOS and Linux, the currently logged in user can be identified with w and who. On macOS the dscl . list /Users | grep -v '_' command can also be used to enumerate user accounts. Environment variables, such as %USERNAME% and $USER, may also be used to access this information.

On network devices, Network Device CLI commands such as `show users` and `show ssh` can be used to display users currently logged into the device.[1][2]

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

G0082: APT38

APT38 is a North Korean state-sponsored threat group that specializes in financial cyber operations; it has been attributed to the Reconnaissance General Bureau.[1] Active since at least 2014, APT38 has targeted banks, financial institutions, casinos, cryptocurrency exchanges, SWIFT system endpoints, and ATMs in at least 38 countries worldwide. Significant operations include the 2016 Bank of Bangladesh heist, during which APT38 stole $81 million, as well as attacks against Bancomext [2] and Banco de Chile [2]; some of their attacks have been destructive.[1][2][3][4]

North Korean group definitions are known to have significant overlap, and some security researchers report all North Korean state-sponsored cyber activity under the name Lazarus Group instead of tracking clusters or subgroups.

GroupEnterprise

G0093: GALLIUM

GALLIUM is a cyberespionage group that has been active since at least 2012, primarily targeting telecommunications companies, financial institutions, and government entities in Afghanistan, Australia, Belgium, Cambodia, Malaysia, Mozambique, the Philippines, Russia, and Vietnam. This group is particularly known for launching Operation Soft Cell, a long-term campaign targeting telecommunications providers.[1] Security researchers have identified GALLIUM as a likely Chinese state-sponsored group, based in part on tools used and TTPs commonly associated with Chinese threat actors.[1][2][3]

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

G0094: Kimsuky

Kimsuky is a Democratic People's Republic of Korea (DPRK)-based cyber espionage group that has been active since at least 2012. The group initially targeted South Korean government agencies, think tanks, and subject-matter experts in various fields. Its operations expanded to include the United Nations and organizations in the government, education, business services, and manufacturing sectors across the United States, Japan, Russia, and Europe. Kimsuky has focused collection on foreign policy and national security issues tied to the Korean Peninsula, nuclear policy, and sanctions. Kimsuky operations have overlapped with those of other North Korean state-sponsored cyber espionage actors as a result of ad hoc collaborations or other limited resource sharing.[1][2][3][4][5][6]

Kimsuky was assessed to be responsible for the 2014 Korea Hydro & Nuclear Power Co. compromise; other notable campaigns include Operation STOLEN PENCIL (2018), Operation Kabar Cobra (2019), and Operation Smoke Screen (2019).[7][8][9] In 2023, Kimsuky was observed using commercial large language models (LLMs) to assist with vulnerability research, scripting, social engineering and reconnaissance.[10]

DPRK threat actor cluster boundaries overlap in open source reporting, with some security researchers consolidating all attributed North Korean state-sponsored cyber activity under Lazarus Group, rather than tracking operationally distinct subgroups.

GroupEnterprise

G1017: Volt Typhoon

Volt Typhoon is a People's Republic of China (PRC) state-sponsored actor that has been active since at least 2021, primarily targeting critical infrastructure organizations in the US and its territories including Guam. Volt Typhoon's targeting and pattern of behavior have been assessed as pre-positioning to enable lateral movement to operational technology (OT) assets for potential destructive or disruptive attacks. Volt Typhoon has emphasized stealth in operations using web shells, living-off-the-land (LOTL) binaries, hands on keyboard activities, and stolen credentials.[1][2][3][4]. The group has leveraged compromised SOHO routers to proxy command and control traffic and obscure its infrastructure, activity associated with the KV botnet.[5].

Reporting indicates a separate initial access cluster, SYLVANITE, has been observed exploiting internet-facing edge devices and transferring access to Volt Typhoon, also tracked as VOLTZITE, for follow-on operations. [6]

GroupEnterprise

G0040: Patchwork

Patchwork is a cyber espionage group that was first observed in December 2015. While the group has not been definitively attributed, circumstantial evidence suggests the group may be a pro-Indian or Indian entity. Patchwork has been seen targeting industries related to diplomatic and government agencies. Much of the code used by this group was copied and pasted from online forums. Patchwork was also seen operating spearphishing campaigns targeting U.S. think tank groups in March and April of 2018.[1] [2][3][4]

GroupEnterprise

G0096: APT41

APT41 is a threat group that researchers have assessed as Chinese state-sponsored espionage group that also conducts financially-motivated operations. Active since at least 2012, APT41 has been observed targeting various industries, including but not limited to healthcare, telecom, technology, finance, education, retail and video game industries in 14 countries.[1] Notable behaviors include using a wide range of malware and tools to complete mission objectives. APT41 overlaps at least partially with public reporting on groups including BARIUM and Winnti Group.[2][3]

GroupEnterprise

G0035: Dragonfly

Dragonfly is a cyber espionage group that has been attributed to Russia's Federal Security Service (FSB) Center 16.[1][2] Active since at least 2010, Dragonfly has targeted defense and aviation companies, government entities, companies related to industrial control systems, and critical infrastructure sectors worldwide through supply chain, spearphishing, and drive-by compromise attacks.[3][4][5][6][7][8][9]

GroupEnterprise

G0050: APT32

APT32 is a suspected Vietnam-based threat group that has been active since at least 2014. The group has targeted multiple private sector industries as well as foreign governments, dissidents, and journalists with a strong focus on Southeast Asian countries like Vietnam, the Philippines, Laos, and Cambodia. They have extensively used strategic web compromises to compromise victims.[1][2][3]

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

G0069: MuddyWater

MuddyWater is a cyber espionage group assessed to be a subordinate element within Iran's Ministry of Intelligence and Security (MOIS).[1] Since at least 2017, MuddyWater has targeted a range of government and private organizations across sectors, including telecommunications, local government, finance, defense, and oil and natural gas organizations, in the Middle East (specifically the UAE and Saudi Arabia), Asia, Africa, Europe, and North America. MuddyWater has reused domains dating back to October 2025, and has a preference for NameCheap and Hosterdaddy Private Limited (AS136557). In late 2025 and early 2026, MuddyWater used commercial satellite internet (i.e., Starlink) for command and control (C2) communication. [2][3][4][5][6][7][8][9][10][11][12][13]

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]

MalwareEnterprise

S0266: TrickBot

TrickBot is a Trojan spyware program written in C++ that first emerged in September 2016 as a possible successor to Dyre. TrickBot was developed and initially used by Wizard Spider for targeting banking sites in North America, Australia, and throughout Europe; it has since been used against all sectors worldwide as part of "big game hunting" ransomware campaigns.[1][2][3][4]

Windows
MalwareEnterprise

S0139: PowerDuke

PowerDuke is a backdoor that was used by APT29 in 2016. It has primarily been delivered through Microsoft Word or Excel attachments containing malicious macros. [1]

Windows
MalwareEnterprise

S1039: Bumblebee

Bumblebee is a custom loader written in C++ that has been used by multiple threat actors, including possible initial access brokers, to download and execute additional payloads since at least March 2022. Bumblebee has been linked to ransomware operations including Conti, Quantum, and Mountlocker and derived its name from the appearance of "bumblebee" in the user-agent.[1][2][3]

Windows
MalwareEnterprise

S0353: NOKKI

NOKKI is a modular remote access tool. The earliest observed attack using NOKKI was in January 2018. NOKKI has significant code overlap with the KONNI malware family. There is some evidence potentially linking NOKKI to APT37.[1][2]

Windows
MalwareEnterprise

S0248: yty

yty is a modular, plugin-based malware framework. The components of the framework are written in a variety of programming languages. [1]

Windows
MalwareEnterprise

S9029: IronWind

IronWind is a custom loader malware that has been in use since at least 2023 by actors including WIRTE to target entities in the Middle East.[1]

Windows
CampaignEnterprise

C0058: SharePoint ToolShell Exploitation

The SharePoint ToolShell Exploitation campaign was conducted in July 2025 and encompassed the first waves of exploitation against incompletely patched spoofing (CVE-2025-49706) and remote code execution (CVE-2025-49704) vulnerabilities affecting on-premises Microsoft SharePoint servers. Later patched and updated as CVE-2025-53770 and CVE-2025-53771, the ToolShell vulnerabilities were widely exploited including by China-based ransomware actor Storm-2603 and espionage actors Threat Group-3390 and ZIRCONIUM. SharePoint ToolShell Exploitation targeted multiple regions and industries including finance, education, energy, and healthcare across Asia, Europe, and the United States.[1][2][3][4][5]

CampaignEnterprise

C0001: Frankenstein

Frankenstein was described by security researchers as a highly-targeted campaign conducted by moderately sophisticated and highly resourceful threat actors in early 2019. The unidentified actors primarily relied on open source tools, including Empire. The campaign name refers to the actors' ability to piece together several unrelated open-source tool components.[1]

CampaignEnterprise

C0018: C0018

C0018 was a month-long ransomware intrusion that successfully deployed AvosLocker onto a compromised network. The unidentified actors gained initial access to the victim network through an exposed server and used a variety of open-source tools prior to executing AvosLocker.[1][2]

CampaignEnterprise

C0061: Operation Digital Eye

Operation Digital Eye was conducted in June and July of 2024 by suspected People's Republic of China (PRC)-nexus threat actors targeting business-to-business IT service providers in Southern Europe. Operation Digital Eye activity included the use of Visual Studio Code tunnels for command and control (C2) and custom lateral movement capabilities. Overlaps in tooling between Digital Eye and previous China-nexus campaigns, Operation Soft Cell and Operation Tainted Love, indicate the potential use of shared vendors or digital quartermasters.[1]

CampaignEnterprise

C0012: Operation CuckooBees

Operation CuckooBees was a cyber espionage campaign targeting technology and manufacturing companies in East Asia, Western Europe, and North America since at least 2019. Security researchers noted the goal of Operation CuckooBees, which was still ongoing as of May 2022, was likely the theft of proprietary information, research and development documents, source code, and blueprints for various technologies. Researchers assessed Operation CuckooBees was conducted by actors affiliated with Winnti Group, APT41, and BARIUM.[1]

CampaignEnterprise

C0002: Night Dragon

Night Dragon was a cyber espionage campaign that targeted oil, energy, and petrochemical companies, along with individuals and executives in Kazakhstan, Taiwan, Greece, and the United States. The unidentified threat actors searched for information related to oil and gas field production systems, financials, and collected data from SCADA systems. Based on the observed techniques, tools, and network activities, security researchers assessed the campaign involved a threat group based in China.[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]

CampaignEnterprise

C0017: C0017

C0017 was an APT41 campaign conducted between May 2021 and February 2022 that successfully compromised at least six U.S. state government networks through the exploitation of vulnerable Internet facing web applications. During C0017, APT41 was quick to adapt and use publicly-disclosed as well as zero-day vulnerabilities for initial access, and in at least two cases re-compromised victims following remediation efforts. The goals of C0017 are unknown, however APT41 was observed exfiltrating Personal Identifiable Information (PII).[1]

Relationship explorer

All related ATT&CK context

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
1.6
Created
Modified
Raw hash
c5fa12e1809eef83...
Imported snapshots across ATT&CK releases(2)
ReleaseBundle importedObject versionModifiedStatusRaw hash
19.21.6Current bundlec5fa12e1809e…
19.11.6Older bundlec5fa12e1809e…
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]
    show_ssh_users_cmd_cisco

    Cisco. (2023, March 7). Cisco IOS Security Command Reference: Commands S to Z . Retrieved July 13, 2022.

    Open source URL
  2. [2]
    US-CERT TA18-106A Network Infrastructure Devices 2018

    US-CERT. (2018, April 20). Russian State-Sponsored Cyber Actors Targeting Network Infrastructure Devices. Retrieved October 19, 2020.

    Open source URL
  3. [3]
    mitre-attackT1033
    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.