Common Step: Pivot on IOC using GTI Relationships

Common Step: Pivot on IOC using GTI Relationships#

Objective#

Explore relationships connected to a specific Indicator of Compromise (IOC) within Google Threat Intelligence (GTI) to discover related entities (other IOCs, threats, etc.).

Scope#

This sub-runbook executes the appropriate gti-mcp.get_entities_related_to_a_... tool based on the input IOC type and desired relationship(s). It returns the discovered related entities.

Inputs#

  • ${IOC_VALUE}: The specific IOC value (e.g., “198.51.100.10”, “evil-domain.com”, “abcdef123456…”, “http://bad.url/path”).

  • ${IOC_TYPE}: The type of IOC (“IP Address”, “Domain”, “File Hash”, “URL”, “Collection”). Note: Added “Collection” type.

  • ${RELATIONSHIP_NAMES}: A list of relationship names to query (e.g., [“resolutions”, “communicating_files”], [“malware_families”, “attack_techniques”]). The available relationships depend on the ${IOC_TYPE}.

Outputs#

  • ${RELATED_ENTITIES}: A structured dictionary or list containing the entities found for each queried relationship.

  • ${PIVOT_STATUS}: Confirmation or status of the pivoting attempt(s).

Tools#

  • gti-mcp: get_entities_related_to_an_ip_address, get_entities_related_to_a_domain, get_entities_related_to_a_file, get_entities_related_to_an_url, get_entities_related_to_a_collection

Workflow Steps & Diagram#

  1. Receive Input: Obtain ${IOC_VALUE}, ${IOC_TYPE}, and ${RELATIONSHIP_NAMES} from the calling runbook. Initialize ${RELATED_ENTITIES} as an empty structure.

  2. Determine GTI Tool: Based on ${IOC_TYPE}, select the correct gti-mcp tool (e.g., get_entities_related_to_an_ip_address for “IP Address”).

  3. Iterate Relationships: Loop through each relationship in ${RELATIONSHIP_NAMES}.

    • Call the selected GTI tool with the appropriate identifier (ip_address, domain, hash, url, id) set to ${IOC_VALUE} and relationship_name=relationship.

    • Store the results under the relationship key within ${RELATED_ENTITIES}.

  4. Return Results: Set ${PIVOT_STATUS} based on the success/failure of the API calls. Return ${RELATED_ENTITIES} and ${PIVOT_STATUS} to the calling runbook.

        sequenceDiagram
    participant CallingRunbook
    participant PivotOnIOC as pivot_on_ioc_gti.md (This Runbook)
    participant GTI as gti-mcp

    CallingRunbook->>PivotOnIOC: Execute GTI Pivot\nInput: IOC_VALUE, IOC_TYPE, RELATIONSHIP_NAMES

    %% Step 2: Determine Tool
    Note over PivotOnIOC: Select GTI tool based on IOC_TYPE

    %% Step 3: Iterate Relationships
    loop For each relationship R in RELATIONSHIP_NAMES
        PivotOnIOC->>GTI: [Selected Tool](identifier=IOC_VALUE, relationship_name=R)
        GTI-->>PivotOnIOC: Related Entities List for R
        Note over PivotOnIOC: Store results in RELATED_ENTITIES[R]
    end

    %% Step 4: Return Results
    Note over PivotOnIOC: Set PIVOT_STATUS
    PivotOnIOC-->>CallingRunbook: Return Results:\nRELATED_ENTITIES,\nPIVOT_STATUS

Completion Criteria#

The relevant GTI relationship queries have been attempted for the specified IOC. The discovered related entities (${RELATED_ENTITIES}) and status (${PIVOT_STATUS}) are available.

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