Runbook: Alert Triage

Runbook: Alert Triage#

Objective#

To provide a standardized process for the initial assessment and triage of incoming security alerts. This runbook guides the analyst in determining if an alert represents a potential threat requiring further investigation or if it can be closed as a false positive or duplicate. The process involves gathering initial context, checking for duplicates, performing basic enrichment, an alert-specific SIEM search, and making an initial assessment to decide on escalation or closure.

Scope#

This runbook covers:

  • Initial review of an alert or case.

  • Gathering context using SOAR and SIEM tools.

  • Checking for duplicate or similar existing SOAR cases.

  • Finding other SOAR cases related by key entities.

  • Performing an initial, targeted SIEM search based on the alert type for immediate context.

  • Basic enrichment of key entities using SIEM and GTI tools.

  • Decision-making for escalation or closure based on predefined criteria and gathered information.

This runbook explicitly excludes:

  • Deep-dive investigation of alerts or entities.

  • Containment or eradication actions.

  • Advanced threat hunting.

Inputs#

  • ${ALERT_ID} or ${CASE_ID}: The identifier for the alert or case to be triaged.

  • *(Optional) ${ALERT_DETAILS}: Initial details provided by the alerting system (e.g., alert name, severity, specific indicators).

  • (Derived) ${KEY_ENTITIES}: Key entities (IPs, domains, hashes, users) extracted from the alert/case during initial context gathering. These are used for enrichment and finding related cases.

  • (Derived) ${ALERT_TYPE}: The type of alert (e.g., “Suspicious Login”, “Malware Detection”, “Network Alert”), used to guide the alert-specific SIEM search.

Outputs#

  • ${ASSESSMENT}: The outcome of the triage (e.g., “False Positive”, “Benign True Positive”, “True Positive/Suspicious”).

  • ${ACTION_TAKEN}: The action performed based on the assessment (e.g., “Closed”, “Escalated”, “Priority Changed”).

  • ${SIMILAR_CASE_IDS}: List of case IDs identified as potentially similar or duplicate by common_steps/check_duplicate_cases.md.

  • ${ENTITY_RELATED_CASES}: List of case IDs related to key entities involved in the current alert/case, found by common_steps/find_relevant_soar_case.md.

  • ${INITIAL_SIEM_CONTEXT}: Summary of findings from the alert-specific SIEM search performed in Step 6.

  • ${ENRICHMENT_RESULTS}: A structured collection of enrichment data for key entities, gathered by common_steps/enrich_ioc.md.

  • ${DOCUMENTATION_STATUS}: Status of the attempt to document findings in the SOAR case via common_steps/document_in_soar.md.

  • ${CLOSURE_STATUS}: Status of the attempt to close the SOAR artifact (case or alert) via common_steps/close_soar_artifact.md, if applicable.

Tools#

  • secops-soar: get_case_full_details, list_alerts_by_case, list_events_by_alert, post_case_comment, change_case_priority, siemplify_get_similar_cases, siemplify_close_case, siemplify_close_alert

  • secops-mcp: lookup_entity, get_ioc_matches

  • gti-mcp: get_file_report, get_domain_report, get_ip_address_report, get_url_report

  • Common Steps: common_steps/check_duplicate_cases.md, common_steps/enrich_ioc.md, common_steps/find_relevant_soar_case.md, common_steps/document_in_soar.md, common_steps/close_soar_artifact.md

Workflow Steps & Diagram#

  1. Receive Alert/Case: Obtain the ${ALERT_ID} or ${CASE_ID}.

  2. Gather Initial Context: Use secops-soar.get_case_full_details or list_alerts_by_case / list_events_by_alert to understand the alert type, severity, involved entities (KEY_ENTITIES), and triggering events.

  3. Check for Duplicates: Execute common_steps/check_duplicate_cases.md with ${CASE_ID}. Obtain ${SIMILAR_CASE_IDS}.

  4. Handle Duplicates: If ${SIMILAR_CASE_IDS} is not empty and duplication is confirmed by analyst:

    • Execute common_steps/document_in_soar.md with ${CASE_ID} and comment “Closing as duplicate of [Similar Case ID]”.

    • Execute common_steps/close_soar_artifact.md with:

      • ${ARTIFACT_ID} = ${CASE_ID} (or ${ALERT_ID})

      • ${ARTIFACT_TYPE} = “Case” (or “Alert”)

      • ${CLOSURE_REASON} = "NOT_MALICIOUS"

      • ${ROOT_CAUSE} = "Similar case is already under investigation"

      • ${CLOSURE_COMMENT} = “Closing as duplicate of [Similar Case ID]”

    • End runbook execution.

  5. Find Entity-Related Cases:

    • Execute common_steps/find_relevant_soar_case.md with SEARCH_TERMS=KEY_ENTITIES (list of entities from Step 2) and CASE_STATUS_FILTER="Opened".

    • Obtain ${ENTITY_RELATED_CASES} (list of potentially relevant open case summaries/IDs).

  6. (New) Alert-Specific SIEM Search:

    • Based on the alert type identified in Step 2, perform an initial targeted search using secops-mcp.search_security_events to gather immediate context. Examples:

      • Suspicious Login: Search for related login events (success/failure) for the user/source IP/hostname around the alert time (e.g., last hour).

      • Malware Detection: Search for process execution, file modification, or network events related to the file hash/endpoint around the alert time.

      • Network Alert: Search for related network flows or DNS lookups involving the source/destination IPs/domains.

    • Store a summary of findings in ${INITIAL_SIEM_CONTEXT}. This helps provide more specific context before broader enrichment.

  7. Basic Enrichment: Initialize ENRICHMENT_RESULTS structure. For each entity Ei in KEY_ENTITIES:

    • Execute common_steps/enrich_ioc.md with IOC_VALUE=Ei and appropriate IOC_TYPE.

    • Store results (GTI_FINDINGS, SIEM_ENTITY_SUMMARY, SIEM_IOC_MATCH_STATUS) in ENRICHMENT_RESULTS[Ei].

  8. Initial Assessment: Based on alert type, ENRICHMENT_RESULTS, ${ENTITY_RELATED_CASES}, ${INITIAL_SIEM_CONTEXT}, and potential known benign patterns (referencing .agentrules/common_benign_alerts.md if available), make an initial assessment:

    • False Positive (FP)

    • Benign True Positive (BTP - expected/authorized activity)

    • Requires Further Investigation (True Positive - TP or Suspicious)

  9. Action Based on Assessment:

    • If FP/BTP:

      • Execute common_steps/document_in_soar.md with ${CASE_ID} and comment explaining FP/BTP reason.

      • Guidance for Closure:

        • Choose an appropriate ${CLOSURE_REASON} (likely NOT_MALICIOUS).

        • Choose a valid ${ROOT_CAUSE} from the SOAR platform’s predefined list (e.g., "Legit action", "Normal behavior", "Other"). Use secops-soar.get_case_settings_root_causes to list valid options if unsure.

      • Execute common_steps/close_soar_artifact.md with ${ARTIFACT_ID} = ${CASE_ID} (or ${ALERT_ID}), ${ARTIFACT_TYPE} = “Case” (or “Alert”), the chosen ${CLOSURE_REASON}/${ROOT_CAUSE}, and ${CLOSURE_COMMENT} = “Closed as FP/BTP during triage.”.

    • If TP/Suspicious:

      • (Optional) Use secops-soar.change_case_priority if needed.

      • Execute common_steps/document_in_soar.md with ${CASE_ID} and comment summarizing initial findings and assessment.

      • Escalate/assign to the appropriate next tier or trigger a relevant investigation runbook (e.g., deep_dive_ioc_analysis.md, suspicious_login_triage.md).

        sequenceDiagram
    participant Analyst
    participant AutomatedAgent as Automated Agent (MCP Client)
    participant SOAR as secops-soar
    participant CheckDuplicates as common_steps/check_duplicate_cases.md
    participant FindCase as common_steps/find_relevant_soar_case.md
    participant EnrichIOC as common_steps/enrich_ioc.md
    participant DocumentInSOAR as common_steps/document_in_soar.md
    participant CloseArtifact as common_steps/close_soar_artifact.md

    Analyst->>AutomatedAgent: Start Alert Triage\nInput: ALERT_ID/CASE_ID

    %% Step 2: Gather Initial Context
    AutomatedAgent->>SOAR: get_case_full_details / list_alerts_by_case / list_events_by_alert
    SOAR-->>AutomatedAgent: Context (KEY_ENTITIES: E1, E2...)

    %% Step 3: Check for Duplicates
    AutomatedAgent->>CheckDuplicates: Execute(Input: CASE_ID)
    CheckDuplicates-->>AutomatedAgent: Results: SIMILAR_CASE_IDS

    %% Step 4: Handle Duplicates
    alt SIMILAR_CASE_IDS not empty & Confirmed Duplicate
        AutomatedAgent->>DocumentInSOAR: Execute(Input: CASE_ID, Comment="Closing as duplicate...")
        DocumentInSOAR-->>AutomatedAgent: Status
        AutomatedAgent->>CloseArtifact: Execute(Input: ARTIFACT_ID=CASE_ID/ALERT_ID, TYPE=..., REASON="Duplicate"...)
        CloseArtifact-->>AutomatedAgent: Status
        AutomatedAgent->>Analyst: End Triage (Duplicate)
    end

    %% Step 5: Find Entity-Related Cases
    AutomatedAgent->>FindCase: Execute(Input: SEARCH_TERMS=KEY_ENTITIES, CASE_STATUS_FILTER="Opened")
    FindCase-->>AutomatedAgent: Results: ENTITY_RELATED_CASES

    %% Step 6: Alert-Specific SIEM Search
    Note over AutomatedAgent: Construct alert-specific SIEM query based on alert type
    AutomatedAgent->>SIEM: search_security_events(text=AlertSpecificQuery, hours_back=1)
    SIEM-->>AutomatedAgent: Initial SIEM Context Results (INITIAL_SIEM_CONTEXT)

    %% Step 7: Basic Enrichment
    loop For each Key Entity Ei
        AutomatedAgent->>EnrichIOC: Execute(Input: IOC_VALUE=Ei, IOC_TYPE=...)
        EnrichIOC-->>AutomatedAgent: Results: Enrichment Data for Ei
    end

    %% Step 8: Initial Assessment
    Note over AutomatedAgent: Assess: FP / BTP / TP / Suspicious based on Context, Enrichment, Related Cases & Initial SIEM Context

    %% Step 9: Action Based on Assessment
    alt FP / BTP
        AutomatedAgent->>DocumentInSOAR: Execute(Input: CASE_ID, Comment="Closing as FP/BTP...")
        DocumentInSOAR-->>AutomatedAgent: Status
        AutomatedAgent->>CloseArtifact: Execute(Input: ARTIFACT_ID=CASE_ID/ALERT_ID, TYPE=..., REASON="FP/BTP"...)
        CloseArtifact-->>AutomatedAgent: Status
        AutomatedAgent->>Analyst: End Triage (FP/BTP)
    else TP / Suspicious
        opt Change Priority
             AutomatedAgent->>SOAR: change_case_priority(...)
             SOAR-->>AutomatedAgent: Status
        end
        AutomatedAgent->>DocumentInSOAR: Execute(Input: CASE_ID, Comment="Initial Findings...")
        DocumentInSOAR-->>AutomatedAgent: Status
        Note over AutomatedAgent: Escalate / Assign / Trigger Next Runbook
        AutomatedAgent->>Analyst: End Triage (Escalated)
    end

Completion Criteria#

The alert or case has been successfully triaged:

  • Initial context has been gathered and understood.

  • A check for duplicate or similar cases has been performed.

  • Relevant existing cases related to key entities have been identified.

  • An alert-specific SIEM search has been conducted for immediate context.

  • Key entities have undergone basic enrichment.

  • An initial assessment (FP, BTP, TP/Suspicious) has been made.

  • Appropriate action (closure or escalation/assignment) has been taken based on the assessment.

  • All steps, findings, and actions have been documented in the SOAR case.

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