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MITRE ATT&CK® Technique

T1566: Phishing

Adversaries may send phishing messages to gain access to victim systems. All forms of phishing are electronically delivered social engineering. Phishing can be targeted, known as spearphishing. In spearphishing, a specific individual, company, or industry will be targeted by the adversary. More generally, adversaries can conduct non-targeted phishing, such as in mass malware spam campaigns.

Adversaries may send victims emails containing malicious attachments or links, typically to execute malicious code on victim systems. Phishing may also be conducted via third-party services, like social media platforms. Phishing may also involve social engineering techniques, such as posing as a trusted source, as well as evasive techniques such as removing or manipulating emails or metadata/headers from compromised accounts being abused to send messages (e.g., Email Hiding Rules).[1][2] Another way to accomplish this is by Email Spoofing[3] the identity of the sender, which can be used to fool both the human recipient as well as automated security tools,[4] or by including the intended target as a party to an existing email thread that includes malicious files or links (i.e., "thread hijacking").[5]

Victims may also receive phishing messages that instruct them to call a phone number where they are directed to visit a malicious URL, download malware,[6][7] or install adversary-accessible remote management tools onto their computer (i.e., User Execution).[8]

EnterpriseT1566TechniqueObject v2.7Modified
Glexia's Take · Automated analysis

Security context for executives and security teams

Automation confidenceMedium

T1566: Phishing describes Adversaries may send phishing messages to gain access to victim systems. All forms of phishing are electronically delivered social engineering. Phishing can be targeted, known as spearphishing. In spearphishing, a specific individual, company, or industry will be targeted by the adversary. More generally, adversaries can conduct non-targeted phishing, such as in mass malware spam campaigns. Adversaries may send victims emails containing malicious attachments or links, typically to execute malicious code on victim s...

Executive priority

T1566: Phishing 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 T1566: Phishing by reviewing the official ATT&CK relationships, mapped tactics (initial-access), supported platforms (Identity Provider, Linux, macOS, Office Suite), 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 T1566: Phishing 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

Phishing

Adversaries may send phishing messages to gain access to victim systems. All forms of phishing are electronically delivered social engineering. Phishing can be targeted, known as spearphishing. In spearphishing, a specific individual, company, or industry will be targeted by the adversary. More generally, adversaries can conduct non-targeted phishing, such as in mass malware spam campaigns.

Adversaries may send victims emails containing malicious attachments or links, typically to execute malicious code on victim systems. Phishing may also be conducted via third-party services, like social media platforms. Phishing may also involve social engineering techniques, such as posing as a trusted source, as well as evasive techniques such as removing or manipulating emails or metadata/headers from compromised accounts being abused to send messages (e.g., Email Hiding Rules).[1][2] Another way to accomplish this is by Email Spoofing[3] the identity of the sender, which can be used to fool both the human recipient as well as automated security tools,[4] or by including the intended target as a party to an existing email thread that includes malicious files or links (i.e., "thread hijacking").[5]

Victims may also receive phishing messages that instruct them to call a phone number where they are directed to visit a malicious URL, download malware,[6][7] or install adversary-accessible remote management tools onto their computer (i.e., User Execution).[8]

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.

ATT&CK relationship table

Related techniques

This mirrors the MITRE pattern of making group, software, campaign, and technique relationships scannable. Relationship notes come from mirrored ATT&CK relationship text when available.

4 rows
DomainIDNameRelationship / procedure
EnterpriseT1566.002Spearphishing LinkSub-techniqueSpearphishing Link subtechnique of this object.
EnterpriseT1566.001Spearphishing AttachmentSub-techniqueSpearphishing Attachment subtechnique of this object.
EnterpriseT1566.004Spearphishing VoiceSub-techniqueSpearphishing Voice subtechnique of this object.
EnterpriseT1566.003Spearphishing via ServiceSub-techniqueSpearphishing via Service subtechnique of this object.
Associated objects

Groups, software, and campaigns

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

G1049: AppleJeus

AppleJeus is a North Korean state-sponsored threat group attributed to the Reconnaissance General Bureau. Associated with the broader Lazarus Group umbrella of actors, AppleJeus has been active since at least 2018 and is closely aligned in resources with TEMP.hermit, another DPRK-affiliated group under the same umbrella.[1] The group’s primary mission is to generate and launder revenue to provide financial support to the government. AppleJeus primarily targets the cryptocurrency industry and is most notably responsible for the 3CX Supply Chain Attack.[2] The group traditionally deploys malicious cryptocurrency software in combination with Phishing. From these compromised environments, it selectively deploys additional backdoors to enable extended operations against high-value financial targets.[3][4]

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

G1041: Sea Turtle

Sea Turtle is a Türkiye-linked threat actor active since at least 2017 performing espionage and service provider compromise operations against victims in Asia, Europe, and North America. Sea Turtle is notable for targeting registrars managing ccTLDs and complex DNS-based intrusions where the threat actor compromised DNS providers to hijack DNS resolution for ultimate victims, enabling Sea Turtle to spoof log in portals and other applications for credential collection.[1][2][3][4]

GroupEnterprise

G0001: Axiom

Axiom is a suspected Chinese cyber espionage group that has targeted the aerospace, defense, government, manufacturing, and media sectors since at least 2008. Some reporting suggests a degree of overlap between Axiom and Winnti Group but the two groups appear to be distinct based on differences in reporting on TTPs and targeting.[1][2][3]

GroupEnterprise

G0115: GOLD SOUTHFIELD

GOLD SOUTHFIELD is a financially motivated threat group active since at least 2018 that operates the REvil Ransomware-as-a Service (RaaS). GOLD SOUTHFIELD provides backend infrastructure for affiliates recruited on underground forums to perpetrate high value deployments. By early 2020, GOLD SOUTHFIELD started capitalizing on the new trend of stealing data and further extorting the victim to pay for their data to not get publicly leaked.[1][2][3][4]

GroupEnterprise

G1055: VOID MANTICORE

VOID MANTICORE is a threat group assessed to operate on behalf of Iran’s Ministry of Intelligence and Security (MOIS).[1] Active since at least mid-2022, VOID MANTICORE has targeted government entities, critical infrastructure, and private sector organizations across Albania, Israel, and the United States.[1][2] VOID MANTICORE conducts destructive cyber operations, combining wiper attacks with hack-and-leak campaigns. The group has operated under multiple public-facing personas, including HomeLand Justice in operations against Albania, Karma and Karma Below in campaigns targeting Israeli organizations, and Handala Hack, its current primary persona, which has claimed activity against Israeli and U.S. entities, including a March 2026 attack against Stryker Corporation.[1][3] VOID MANTICORE has been observed collaborating with Scarred Manticore, which has been linked to initial access operations preceding VOID MANTICORE’s activity.[4]

MalwareEnterprise

S1073: Royal

Royal is ransomware that first appeared in early 2022; a version that also targets ESXi servers was later observed in February 2023. Royal employs partial encryption and multiple threads to evade detection and speed encryption. Royal has been used in attacks against multiple industries worldwide--including critical infrastructure. Security researchers have identified similarities in the encryption routines and TTPs used in Royal and Conti attacks and noted a possible connection between their operators.[1][2][3][4][5]

WindowsESXi
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
2.7
Created
Modified
Raw hash
42b57f03efcc89cd...
Imported snapshots across ATT&CK releases(2)
ReleaseBundle importedObject versionModifiedStatusRaw hash
19.22.7Current bundle42b57f03efcc…
19.12.7Older bundle42b57f03efcc…
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]
    Microsoft OAuth Spam 2022

    Microsoft. (2023, September 22). Malicious OAuth applications abuse cloud email services to spread spam. Retrieved March 13, 2023.

    Open source URL
  2. [2]
    Palo Alto Unit 42 VBA Infostealer 2014

    Vicky Ray and Rob Downs. (2014, October 29). Examining a VBA-Initiated Infostealer Campaign. Retrieved March 13, 2023.

    Open source URL
  3. [3]
    Proofpoint-spoof

    Proofpoint. (n.d.). What Is Email Spoofing?. Retrieved February 24, 2023.

    Open source URL
  4. [4]
    cyberproof-double-bounce

    Itkin, Liora. (2022, September 1). Double-bounced attacks with email spoofing . Retrieved February 24, 2023.

    Open source URL
  5. [5]
    phishing-krebs

    Brian Krebs. (2024, March 28). Thread Hijacking: Phishes That Prey on Your Curiosity. Retrieved September 27, 2024.

    Open source URL
  6. [6]
    sygnia Luna Month

    Oren Biderman, Tomer Lahiyani, Noam Lifshitz, Ori Porag. (n.d.). LUNA MOTH: THE THREAT ACTORS BEHIND RECENT FALSE SUBSCRIPTION SCAMS. Retrieved February 2, 2023.

    Open source URL
  7. [7]
    CISA Remote Monitoring and Management Software

    CISA. (n.d.). Protecting Against Malicious Use of Remote Monitoring and Management Software. Retrieved February 2, 2023.

    Open source URL
  8. [8]
    Unit42 Luna Moth

    Kristopher Russo. (n.d.). Luna Moth Callback Phishing Campaign. Retrieved February 2, 2023.

    Open source URL
  9. [9]
    mitre-attackT1566
    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.