MITRE ATT&CK T1534: Internal Spearphishing
When to use this skill
Use this skill when the task involves T1534, Internal Spearphishing, enterprise ATT&CK, TTP mapping, detection engineering, hunting, incident-response enrichment, control validation, or authorized adversary-emulation planning. Treat it as a defensive analysis aid: keep outputs focused on understanding, detecting, mitigating, and safely validating this ATT&CK technique.
Technique context
- ATT&CK domain: enterprise
- ATT&CK ID: T1534
- Technique name: Internal Spearphishing
- Type: technique
- ATT&CK URL: https://attack.mitre.org/techniques/T1534
- Tactics: lateral-movement
- Platforms: Linux, macOS, Office Suite, SaaS, Windows
- Required permissions: Not specified
- Effective permissions: Not specified
- Defenses bypassed: Not specified
ATT&CK description
After they already have access to accounts or systems within the environment, adversaries may use internal spearphishing to gain access to additional information or compromise other users within the same organization. Internal spearphishing is multi-staged campaign where a legitimate account is initially compromised either by controlling the user's device or by compromising the account credentials of the user. Adversaries may then attempt to take advantage of the trusted internal account to increase the likelihood of tricking more victims into falling for phish attempts, often incorporating Impersonation.(Citation: Trend Micro - Int SP)
For example, adversaries may leverage Spearphishing Attachment or Spearphishing Link as part of internal spearphishing to deliver a payload or redirect to an external site to capture credentials through Input Capture on sites that mimic login interfaces.
Adversaries may also leverage internal chat apps, such as Microsoft Teams, to spread malicious content or engage users in attempts to capture sensitive information and/or credentials.(Citation: Int SP - chat apps)
Agent workflow
- Clarify scope: identify the system, asset class, log sources, cloud or endpoint platform, and whether the user wants triage, detection, coverage assessment, or safe emulation planning.
- Load bundled resources as needed: use
references/technique-profile.json for structured metadata, references/detection-and-mitigation.md for triage and telemetry guidance, references/known-threat-context.md for ATT&CK relationship context, and templates/ for repeatable outputs.
- Map observations to ATT&CK: compare the user's evidence to the ATT&CK description, tactics, platforms, and known procedure patterns before asserting a match.
- Produce defensive outputs: prioritize hypotheses, telemetry requirements, detection logic ideas, validation steps, containment guidance, and mitigations.
- Preserve uncertainty: distinguish confirmed evidence, plausible indicators, assumptions, and gaps. Recommend what to collect next.
- Stay safe: do not provide malware, credential theft, persistence, evasion, destructive automation, or unauthorized exploitation instructions. For adversary emulation, keep steps bounded to approved lab or control-validation contexts and omit operational abuse details.
Bundled resources
references/technique-profile.json: machine-readable ATT&CK metadata for this technique.references/detection-and-mitigation.md: detection notes, telemetry checklist, triage questions, mitigation candidates, and false-positive considerations.references/known-threat-context.md: ATT&CK relationship context with attribution cautions.templates/detection-brief.md: detection engineering brief template.templates/hunt-plan.md: threat hunt plan template.templates/incident-response-note.md: incident response note template.templates/coverage-assessment.md: ATT&CK coverage assessment template.scripts/render_brief.py: local helper that renders a Markdown defensive brief from technique-profile.json.assets/output-schema.json: JSON schema for structured technique analysis outputs.
To generate a quick brief, run python scripts/render_brief.py --output brief.md from inside this skill directory, or adapt the templates directly.
Detection guidance
No ATT&CK detection guidance was present in the source STIX object.
Useful telemetry and data sources
- Not specified in the STIX object.
Mitigations to consider
- No ATT&CK mitigation relationships were present in the source STIX bundle.
Known threat context
Use these examples only as contextual leads, not as proof that an observed event is this technique:
- APT-C-36 (intrusion-set)
- Gamaredon Group (intrusion-set)
- HEXANE (intrusion-set)
- Kimsuky (intrusion-set)
- Leviathan (intrusion-set)
- MuddyWater (intrusion-set)
- Operation Dream Job (campaign)
- SameCoin (malware)
Recommended output pattern
When responding with this skill, structure the answer as:
- Assessment: whether the evidence supports this ATT&CK mapping and why.
- Evidence: specific indicators, logs, behaviors, and assumptions.
- Detection: telemetry sources, analytic logic, and tuning considerations.
- Response: containment, eradication, recovery, and validation actions.
- Coverage gaps: missing logs, sensors, controls, or environmental details.
- References: include the ATT&CK URL and any user-provided evidence references.
ATT&CK contributors
- Tim MalcomVetter
- Swetha Prabakaran, Microsoft Threat Intelligence Center (MSTIC)
1---2name: attack-ent-t1534-internal-spearphishing3description: Analyze MITRE ATT&CK T1534 Internal Spearphishing in the enterprise matrix. Use for TTP triage, detection engineering, hunting, defensive emulation planning, mitigations, incident response mapping, ATT&CK coverage, or questions mentioning T1534, Internal Spearphishing, or enterprise ATT&CK. After they already have access to accounts or systems within the environment, adversaries may use internal spearphishing to gain access to additional information or compromise other users within the same organization.4license: MITRE ATT&CK Terms of Use apply to ATT&CK-derived content. See h5---67# MITRE ATT&CK T1534: Internal Spearphishing89## When to use this skill1011Use this skill when the task involves T1534, Internal Spearphishing, enterprise ATT&CK, TTP mapping, detection engineering, hunting, incident-response enrichment, control validation, or authorized adversary-emulation planning. Treat it as a defensive analysis aid: keep outputs focused on understanding, detecting, mitigating, and safely validating this ATT&CK technique.1213## Technique context1415- ATT&CK domain: enterprise16- ATT&CK ID: T153417- Technique name: Internal Spearphishing18- Type: technique19- ATT&CK URL: https://attack.mitre.org/techniques/T153420- Tactics: lateral-movement21- Platforms: Linux, macOS, Office Suite, SaaS, Windows22- Required permissions: Not specified23- Effective permissions: Not specified24- Defenses bypassed: Not specified2526## ATT&CK description2728After they already have access to accounts or systems within the environment, adversaries may use internal spearphishing to gain access to additional information or compromise other users within the same organization. Internal spearphishing is multi-staged campaign where a legitimate account is initially compromised either by controlling the user's device or by compromising the account credentials of the user. Adversaries may then attempt to take advantage of the trusted internal account to increase the likelihood of tricking more victims into falling for phish attempts, often incorporating [Impersonation](https://attack.mitre.org/techniques/T1684/001).(Citation: Trend Micro - Int SP)2930For example, adversaries may leverage [Spearphishing Attachment](https://attack.mitre.org/techniques/T1566/001) or [Spearphishing Link](https://attack.mitre.org/techniques/T1566/002) as part of internal spearphishing to deliver a payload or redirect to an external site to capture credentials through [Input Capture](https://attack.mitre.org/techniques/T1056) on sites that mimic login interfaces.3132Adversaries may also leverage internal chat apps, such as Microsoft Teams, to spread malicious content or engage users in attempts to capture sensitive information and/or credentials.(Citation: Int SP - chat apps)3334## Agent workflow35361. Clarify scope: identify the system, asset class, log sources, cloud or endpoint platform, and whether the user wants triage, detection, coverage assessment, or safe emulation planning.372. Load bundled resources as needed: use `references/technique-profile.json` for structured metadata, `references/detection-and-mitigation.md` for triage and telemetry guidance, `references/known-threat-context.md` for ATT&CK relationship context, and `templates/` for repeatable outputs.383. Map observations to ATT&CK: compare the user's evidence to the ATT&CK description, tactics, platforms, and known procedure patterns before asserting a match.394. Produce defensive outputs: prioritize hypotheses, telemetry requirements, detection logic ideas, validation steps, containment guidance, and mitigations.405. Preserve uncertainty: distinguish confirmed evidence, plausible indicators, assumptions, and gaps. Recommend what to collect next.416. Stay safe: do not provide malware, credential theft, persistence, evasion, destructive automation, or unauthorized exploitation instructions. For adversary emulation, keep steps bounded to approved lab or control-validation contexts and omit operational abuse details.4243## Bundled resources4445- `references/technique-profile.json`: machine-readable ATT&CK metadata for this technique.46- `references/detection-and-mitigation.md`: detection notes, telemetry checklist, triage questions, mitigation candidates, and false-positive considerations.47- `references/known-threat-context.md`: ATT&CK relationship context with attribution cautions.48- `templates/detection-brief.md`: detection engineering brief template.49- `templates/hunt-plan.md`: threat hunt plan template.50- `templates/incident-response-note.md`: incident response note template.51- `templates/coverage-assessment.md`: ATT&CK coverage assessment template.52- `scripts/render_brief.py`: local helper that renders a Markdown defensive brief from `technique-profile.json`.53- `assets/output-schema.json`: JSON schema for structured technique analysis outputs.5455To generate a quick brief, run `python scripts/render_brief.py --output brief.md` from inside this skill directory, or adapt the templates directly.5657## Detection guidance5859No ATT&CK detection guidance was present in the source STIX object.6061## Useful telemetry and data sources6263- Not specified in the STIX object.6465## Mitigations to consider6667- No ATT&CK mitigation relationships were present in the source STIX bundle.6869## Known threat context7071Use these examples only as contextual leads, not as proof that an observed event is this technique:7273- APT-C-36 (intrusion-set)74- Gamaredon Group (intrusion-set)75- HEXANE (intrusion-set)76- Kimsuky (intrusion-set)77- Leviathan (intrusion-set)78- MuddyWater (intrusion-set)79- Operation Dream Job (campaign)80- SameCoin (malware)8182## Recommended output pattern8384When responding with this skill, structure the answer as:8586- Assessment: whether the evidence supports this ATT&CK mapping and why.87- Evidence: specific indicators, logs, behaviors, and assumptions.88- Detection: telemetry sources, analytic logic, and tuning considerations.89- Response: containment, eradication, recovery, and validation actions.90- Coverage gaps: missing logs, sensors, controls, or environmental details.91- References: include the ATT&CK URL and any user-provided evidence references.9293## ATT&CK contributors9495- Tim MalcomVetter96- Swetha Prabakaran, Microsoft Threat Intelligence Center (MSTIC)
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