Files
Anthropic-Cybersecurity-Skills/skills/hunting-for-spearphishing-indicators/SKILL.md
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mukul975 cb8d79e068 Map all 754 skills to MITRE ATT&CK v19.1
- Add validated mitre_attack frontmatter to all 754 skills (286 distinct
  techniques), verified against MITRE ATT&CK v19.1 via the official
  mitreattack-python library: 0 revoked, deprecated, or invalid IDs
- Curate precise per-skill technique IDs for forensics, malware-analysis,
  threat-intel, and red-team skills (e.g. DCSync -> T1003.006,
  Kerberoasting -> T1558.003, Pass-the-Ticket -> T1550.003)
- Reconcile v19.1 tactic restructuring: Defense Evasion split into
  Stealth (TA0005) and Defense Impairment (TA0112); revoked T1562.*
  family and T1070.001/.002 remapped to active equivalents (T1685.*)
- Normalize word-split tags across 35 skills (remove filename-derived
  stopword tags, add semantic cybersecurity tags)
- Add api-reference.md for 3 skills that were missing it
- Update README ATT&CK section with accurate v19.1 tactic distribution
2026-06-01 12:13:29 +02:00

3.3 KiB

name, description, domain, subdomain, tags, version, author, license, d3fend_techniques, nist_csf, mitre_attack
name description domain subdomain tags version author license d3fend_techniques nist_csf mitre_attack
hunting-for-spearphishing-indicators Hunt for spearphishing campaign indicators across email logs, endpoint telemetry, and network data to detect targeted email attacks. cybersecurity threat-hunting
threat-hunting
mitre-attack
spearphishing
initial-access
email-security
t1566
proactive-detection
1.0 mahipal Apache-2.0
File Metadata Consistency Validation
Application Protocol Command Analysis
Identifier Analysis
Content Format Conversion
Message Analysis
DE.CM-01
DE.AE-02
DE.AE-07
ID.RA-05
T1046
T1057
T1082
T1083
T1566

Hunting For Spearphishing Indicators

When to Use

  • When proactively hunting for indicators of hunting for spearphishing indicators in the environment
  • After threat intelligence indicates active campaigns using these techniques
  • During incident response to scope compromise related to these techniques
  • When EDR or SIEM alerts trigger on related indicators
  • During periodic security assessments and purple team exercises

Prerequisites

  • EDR platform with process and network telemetry (CrowdStrike, MDE, SentinelOne)
  • SIEM with relevant log data ingested (Splunk, Elastic, Sentinel)
  • Sysmon deployed with comprehensive configuration
  • Windows Security Event Log forwarding enabled
  • Threat intelligence feeds for IOC correlation

Workflow

  1. Formulate Hypothesis: Define a testable hypothesis based on threat intelligence or ATT&CK gap analysis.
  2. Identify Data Sources: Determine which logs and telemetry are needed to validate or refute the hypothesis.
  3. Execute Queries: Run detection queries against SIEM and EDR platforms to collect relevant events.
  4. Analyze Results: Examine query results for anomalies, correlating across multiple data sources.
  5. Validate Findings: Distinguish true positives from false positives through contextual analysis.
  6. Correlate Activity: Link findings to broader attack chains and threat actor TTPs.
  7. Document and Report: Record findings, update detection rules, and recommend response actions.

Key Concepts

Concept Description
T1566.001 Spearphishing Attachment
T1566.002 Spearphishing Link
T1566.003 Spearphishing via Service

Tools & Systems

Tool Purpose
CrowdStrike Falcon EDR telemetry and threat detection
Microsoft Defender for Endpoint Advanced hunting with KQL
Splunk Enterprise SIEM log analysis with SPL queries
Elastic Security Detection rules and investigation timeline
Sysmon Detailed Windows event monitoring
Velociraptor Endpoint artifact collection and hunting
Sigma Rules Cross-platform detection rule format

Common Scenarios

  1. Scenario 1: Macro-enabled Excel executing PowerShell downloader
  2. Scenario 2: HTML smuggling delivering ISO with LNK payload
  3. Scenario 3: Credential harvesting link as SharePoint notification
  4. Scenario 4: QR code phishing in PDF attachment

Output Format

Hunt ID: TH-HUNTIN-[DATE]-[SEQ]
Technique: T1566.001
Host: [Hostname]
User: [Account context]
Evidence: [Log entries, process trees, network data]
Risk Level: [Critical/High/Medium/Low]
Confidence: [High/Medium/Low]
Recommended Action: [Containment, investigation, monitoring]