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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 v1.6 Modified
Glexia's Take

Analyst context for executives and security teams

Analyst confidence Medium

System Owner/User Discovery is a basic but high-value discovery behavior: an intruder tries to learn who uses a machine or network device, whether someone is currently active, and which accounts are present. For leaders, this matters because that context helps an adversary decide what to do next—such as whether to continue, avoid user attention, or tailor follow-on actions around specific identities or systems.

Executive priority

Treat this as an early-warning discovery signal, not as a standalone impact event. It is relevant to SOC readiness, identity governance, incident triage, and network device administration because the same behavior can appear on Windows, Linux, macOS, and network devices. Executives should ask whether the organization can distinguish routine administrative user checks from unusual enumeration after initial access, especially on servers, privileged workstations, and infrastructure devices.

Technical view

ATT&CK lists this as an enterprise Discovery technique across Linux, macOS, Windows, and Network Devices. Examples include use of commands/utilities such as whoami, w, who, macOS dscl user listing, environment variables like %USERNAME% and $USER, and network device CLI commands such as show users and show ssh. MITRE provides no official detection text, but the relationship context includes DET0093, Behavioral Detection of User Discovery via Local and Remote Enumeration. SOC and IR teams should validate visibility into local command execution, process ownership, session state, account enumeration, and network device CLI activity, then correlate with surrounding discovery, credential access, lateral movement, or remote administration context.

Likely telemetry

  • Endpoint process creation and command-line telemetry for user/session discovery utilities
  • Shell history or command execution records where available on Linux and macOS
  • Windows environment variable usage and process context where captured by endpoint telemetry
  • Running process ownership metadata
  • File and directory ownership metadata when queried or enumerated

Detection direction

  • Baseline legitimate administrative, help desk, deployment, and monitoring use of user-discovery commands before alerting broadly.
  • Prioritize alerts when user discovery occurs from unusual parent processes, unexpected accounts, newly accessed hosts, remote sessions, or shortly after other discovery behavior.
  • For network devices, confirm CLI command accounting is enabled; otherwise show users/show ssh activity may not be visible to the SOC.
  • Tune for sequence and context rather than single commands alone, because utilities such as whoami, who, w, and account/session queries are common in normal operations.
  • Use relationship context from DET0093 as a validation direction for behavioral detection of local and remote user enumeration, while recognizing the supplied ATT&CK object does not include a detailed detection analytic.

Mitigation priorities

  • Ensure endpoint and network device logging is sufficient to reconstruct command execution, session state, and account context during investigations.
  • Restrict and monitor administrative access to network devices and high-value systems so user/session enumeration is attributable to known operators.
  • Apply least-privilege and identity hygiene so discovery of usernames or active users does not easily translate into privileged follow-on activity.
  • Harden remote administration paths and review whether service accounts or automation routinely perform user discovery in ways that obscure suspicious behavior.
  • Document detection and logging coverage as compliance and incident-response evidence, especially for privileged systems and critical infrastructure-facing network devices.
Analyst notes and limits

ATT&CK maps this technique to many historical campaigns and groups, including examples across espionage, financially motivated, ransomware, and critical-infrastructure-relevant contexts. That breadth means the behavior is common tradecraft rather than a strong attribution indicator. Its defensive value is highest when correlated with timing, source account, host role, remote access method, and adjacent ATT&CK discovery or credential behaviors.

MITRE does not provide official detection guidance for this object, and the supplied relationship descriptions are not complete for every related campaign or group. This take does not establish active exploitation, customer exposure, or guaranteed detection coverage. Local baselines, logging configuration, and asset criticality are required to decide alert severity.

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

Group Enterprise

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.

Group Enterprise

G1036: Moonstone Sleet

Moonstone Sleet is a North Korean-linked threat actor executing both financially motivated attacks and espionage operations. The group previously overlapped significantly with another North Korean-linked entity, Lazarus Group, but has differentiated its tradecraft since 2023. Moonstone Sleet is notable for creating fake companies and personas to interact with victim entities, as well as developing unique malware such as a variant delivered via a fully functioning game.[1]

Group Enterprise

G0061: FIN8

FIN8 is a financially motivated threat group that has been active since at least January 2016, and known for targeting organizations in the hospitality, retail, entertainment, insurance, technology, chemical, and financial sectors. In June 2021, security researchers detected FIN8 switching from targeting point-of-sale (POS) devices to distributing a number of ransomware variants.[1][2][3][4]

Group Enterprise

G0004: Ke3chang

Ke3chang is a threat group attributed to actors operating out of China. Ke3chang has targeted oil, government, diplomatic, military, and NGOs in Central and South America, the Caribbean, Europe, and North America since at least 2010.[1][2][3][4]

Group Enterprise

G0046: FIN7

FIN7 is a financially-motivated threat group that has been active since 2013. FIN7 has targeted the retail, restaurant, hospitality, software, consulting, financial services, medical equipment, cloud services, media, food and beverage, transportation, pharmaceutical, and utilities industries in the United States. A portion of FIN7 was operated out of a front company called Combi Security and often used point-of-sale malware for targeting efforts. Since 2020, FIN7 shifted operations to big game hunting (BGH), including use of REvil ransomware and their own Ransomware-as-a-Service (RaaS), Darkside. FIN7 may be linked to the Carbanak Group, but multiple threat groups have been observed using Carbanak, leading these groups to be tracked separately.[1][2][3][4][5][6][7]

Group Enterprise

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]

Group Enterprise

G1035: Winter Vivern

Winter Vivern is a group linked to Russian and Belorussian interests active since at least 2020 targeting various European government and NGO entities, along with sporadic targeting of Indian and US victims. The group leverages a combination of document-based phishing activity and server-side exploitation for initial access, leveraging adversary-controlled and -created infrastructure for follow-on command and control.[1][2][3][4][5]

Group Enterprise

G0073: APT19

APT19 is a Chinese-based threat group that has targeted a variety of industries, including defense, finance, energy, pharmaceutical, telecommunications, high tech, education, manufacturing, and legal services. In 2017, a phishing campaign was used to target seven law and investment firms. [1] Some analysts track APT19 and Deep Panda as the same group, but it is unclear from open source information if the groups are the same. [2] [3] [4]

Group Enterprise

G0051: FIN10

FIN10 is a financially motivated threat group that has targeted organizations in North America since at least 2013 through 2016. The group uses stolen data exfiltrated from victims to extort organizations. [1]

Group Enterprise

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]

Group Enterprise

G0087: APT39

APT39 is one of several names for cyber espionage activity conducted by the Iranian Ministry of Intelligence and Security (MOIS) through the front company Rana Intelligence Computing since at least 2014. APT39 has primarily targeted the travel, hospitality, academic, and telecommunications industries in Iran and across Asia, Africa, Europe, and North America to track individuals and entities considered to be a threat by the MOIS.[1][2][3][4][5]

Malware Enterprise

S0428: PoetRAT

PoetRAT is a remote access trojan (RAT) that was first identified in April 2020. PoetRAT has been used in multiple campaigns against the private and public sectors in Azerbaijan, including ICS and SCADA systems in the energy sector. The STIBNITE activity group has been observed using the malware. PoetRAT derived its name from references in the code to poet William Shakespeare. [1][2][3]

Windows
Malware Enterprise

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
Malware Enterprise

S0596: ShadowPad

ShadowPad is a modular backdoor that was first identified in a supply chain compromise of the NetSarang software in mid-July 2017. The malware was originally thought to be exclusively used by APT41, but has since been observed to be used by various Chinese threat activity groups. [1][2][3]

Windows
Malware Enterprise

S0367: Emotet

Emotet is a modular malware variant which is primarily used as a downloader for other malware variants such as TrickBot and IcedID. Emotet first emerged in June 2014, initially targeting the financial sector, and has expanded to multiple verticals over time.[1]

Windows
Malware Enterprise

S0414: BabyShark

BabyShark is a Microsoft Visual Basic (VB) script-based malware family that is believed to be associated with several North Korean campaigns. [1]

Windows
Campaign Enterprise

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]

Campaign Enterprise

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]

Campaign Enterprise

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

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
19.1
Object version
1.6
Created
Modified
Raw hash
c5fa12e1809eef83...
Imported snapshots across ATT&CK releases (1)
Release Bundle imported Object version Modified Status Raw hash
19.1 1.6 Current bundle c5fa12e1809e…
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-attack T1033
    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.