MITRE ATT&CK T1568.003: DNS Calculation
When to use this skill
Use this skill when the task involves T1568.003, DNS Calculation, 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 sub-technique.
Technique context
- ATT&CK domain: enterprise
- ATT&CK ID: T1568.003
- Technique name: DNS Calculation
- Type: sub-technique
- ATT&CK URL: https://attack.mitre.org/techniques/T1568/003
- Tactics: command-and-control
- Platforms: ESXi, Linux, macOS, Windows
- Required permissions: Not specified
- Effective permissions: Not specified
- Defenses bypassed: Not specified
ATT&CK description
Adversaries may perform calculations on addresses returned in DNS results to determine which port and IP address to use for command and control, rather than relying on a predetermined port number or the actual returned IP address. A IP and/or port number calculation can be used to bypass egress filtering on a C2 channel.(Citation: Meyers Numbered Panda)
One implementation of DNS Calculation is to take the first three octets of an IP address in a DNS response and use those values to calculate the port for command and control traffic.(Citation: Meyers Numbered Panda)(Citation: Moran 2014)(Citation: Rapid7G20Espionage)
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:
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.
1---2name: attack-ent-t1568-003-dns-calculation3description: Analyze MITRE ATT&CK T1568.003 DNS Calculation in the enterprise matrix. Use for TTP triage, detection engineering, hunting, defensive emulation planning, mitigations, incident response mapping, ATT&CK coverage, or questions mentioning T1568.003, DNS Calculation, or enterprise ATT&CK. Adversaries may perform calculations on addresses returned in DNS results to determine which port and IP address to use for command and control, rather than relying on a predetermined port number or the actual returned…4license: MITRE ATT&CK Terms of Use apply to ATT&CK-derived content. See h5---67# MITRE ATT&CK T1568.003: DNS Calculation89## When to use this skill1011Use this skill when the task involves T1568.003, DNS Calculation, 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 sub-technique.1213## Technique context1415- ATT&CK domain: enterprise16- ATT&CK ID: T1568.00317- Technique name: DNS Calculation18- Type: sub-technique19- ATT&CK URL: https://attack.mitre.org/techniques/T1568/00320- Tactics: command-and-control21- Platforms: ESXi, Linux, macOS, Windows22- Required permissions: Not specified23- Effective permissions: Not specified24- Defenses bypassed: Not specified2526## ATT&CK description2728Adversaries may perform calculations on addresses returned in DNS results to determine which port and IP address to use for command and control, rather than relying on a predetermined port number or the actual returned IP address. A IP and/or port number calculation can be used to bypass egress filtering on a C2 channel.(Citation: Meyers Numbered Panda)2930One implementation of [DNS Calculation](https://attack.mitre.org/techniques/T1568/003) is to take the first three octets of an IP address in a DNS response and use those values to calculate the port for command and control traffic.(Citation: Meyers Numbered Panda)(Citation: Moran 2014)(Citation: Rapid7G20Espionage)3132## Agent workflow33341. 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.352. 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.363. 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.374. Produce defensive outputs: prioritize hypotheses, telemetry requirements, detection logic ideas, validation steps, containment guidance, and mitigations.385. Preserve uncertainty: distinguish confirmed evidence, plausible indicators, assumptions, and gaps. Recommend what to collect next.396. 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.4041## Bundled resources4243- `references/technique-profile.json`: machine-readable ATT&CK metadata for this technique.44- `references/detection-and-mitigation.md`: detection notes, telemetry checklist, triage questions, mitigation candidates, and false-positive considerations.45- `references/known-threat-context.md`: ATT&CK relationship context with attribution cautions.46- `templates/detection-brief.md`: detection engineering brief template.47- `templates/hunt-plan.md`: threat hunt plan template.48- `templates/incident-response-note.md`: incident response note template.49- `templates/coverage-assessment.md`: ATT&CK coverage assessment template.50- `scripts/render_brief.py`: local helper that renders a Markdown defensive brief from `technique-profile.json`.51- `assets/output-schema.json`: JSON schema for structured technique analysis outputs.5253To generate a quick brief, run `python scripts/render_brief.py --output brief.md` from inside this skill directory, or adapt the templates directly.5455## Detection guidance5657No ATT&CK detection guidance was present in the source STIX object.5859## Useful telemetry and data sources6061- Not specified in the STIX object.6263## Mitigations to consider6465- No ATT&CK mitigation relationships were present in the source STIX bundle.6667## Known threat context6869Use these examples only as contextual leads, not as proof that an observed event is this technique:7071- APT12 (intrusion-set)7273## Recommended output pattern7475When responding with this skill, structure the answer as:7677- Assessment: whether the evidence supports this ATT&CK mapping and why.78- Evidence: specific indicators, logs, behaviors, and assumptions.79- Detection: telemetry sources, analytic logic, and tuning considerations.80- Response: containment, eradication, recovery, and validation actions.81- Coverage gaps: missing logs, sensors, controls, or environmental details.82- References: include the ATT&CK URL and any user-provided evidence references.
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