{
  "hunt": {
    "meta": {
      "tlp": "clear",
      "hunt": {
        "handoff": "promote-to-detection",
        "trigger": "intel-report",
        "methodology": "model-assisted",
        "applicability": "campaign-specific",
        "justification": "The Rust standard library is used in critical internet-facing services; vulnerabilities that allow safe code to trigger memory corruption provide a direct path for initial access through public-facing applications."
      },
      "name": "Rust Standard Library Memory Safety Exploitation",
      "type": "investigation",
      "labels": [
        "hunt",
        "attack.t1190",
        "attack.t1499",
        "impact",
        "initial access"
      ],
      "related": [
        {
          "hunt": "generic-c0000005-memory-corruption-triage",
          "reason": "A broader hunt for all memory corruption crashes would catch these triggers but with significantly more noise.",
          "relation": "out-of-scope-alternative"
        }
      ],
      "targets": {
        "hunter": {
          "name": "Hunt agent",
          "agent": true
        },
        "analyst": {
          "name": "Tier-2 analyst",
          "role": "analyst"
        },
        "endpoint": {
          "name": "Endpoint telemetry (hb_ surfaces)",
          "category": "endpoint",
          "telemetry": [
            "endpoint"
          ]
        }
      },
      "analysis": "A detection rule for 'c0000005' crashes is too noisy for production; this hunt filters for specific Rust modules, corroborates with vulnerability status, and pivots to fileless process activity to confirm exploit success.",
      "coverage": [
        {
          "stage": "vulnerability-inventory",
          "steps": [
            "identify-vulnerable-rust-assets"
          ],
          "status": "covered"
        },
        {
          "stage": "memory-safety-exploit-trigger",
          "steps": [
            "rust-logic-crashes"
          ],
          "status": "covered"
        },
        {
          "stage": "application-crash-violation",
          "steps": [
            "rust-logic-crashes",
            "rare-fileless-processes"
          ],
          "status": "covered"
        }
      ],
      "scenario": {
        "stages": [
          {
            "name": "Identification of Vulnerable Rust Library Versions",
            "slug": "vulnerability-inventory",
            "tactic": "initial-access",
            "techniques": [
              "T1190"
            ],
            "observables": [
              "Rust core/std version < 1.97.0",
              "CVE-2015-20001 (BinaryHeap)",
              "CVE-2020-36323 (String joining)",
              "library/core/src/iter/adapters/map_windows.rs"
            ]
          },
          {
            "name": "Triggering Undefined Behavior via Safe APIs",
            "slug": "memory-safety-exploit-trigger",
            "tactic": "initial-access",
            "techniques": [
              "T1190"
            ],
            "observables": [
              "MapWindows::clone",
              "self.buffer",
              "self.start",
              "self.as_array_ref().clone()",
              "BinaryHeap sift_up",
              "BinaryHeap sift_down_range"
            ]
          },
          {
            "name": "Memory Safety Violation and Process Crash",
            "slug": "application-crash-violation",
            "tactic": "impact",
            "techniques": [
              "T1499"
            ],
            "observables": [
              "exception_code: c0000005",
              "str.rs",
              "unix.rs",
              "data.sub",
              "v.begin",
              "v.end",
              "drop_in_place on uninitialized memory",
              "segmentation fault"
            ]
          }
        ],
        "summary": "Microsoft FORGE Lab researchers identified memory-safety vulnerabilities in the Rust standard library (core and std) using agentic AI tools. These flaws, including panic-safety bugs in Iterator::map_windows and race conditions in system interactions, allow safe Rust code to trigger undefined behavior or memory corruption, potentially leading to application crashes in public-facing services."
      },
      "severity": "high",
      "rationale": "The lead query identifies vulnerable device UIDs; the analyst must translate these to hostnames or use the returned inventory data to populate the 'scope_hosts' parameter for the behavioral branches.",
      "guardrails": {
        "claims": "no_unsupported",
        "evidence": "citation_required",
        "telemetry": "untrusted",
        "missing_data": "not_benign"
      },
      "hypothesis": "An adversary is exploiting memory-safety vulnerabilities in the Rust standard library (core and std) to trigger undefined behavior and achieve code execution in public-facing applications.",
      "parameters": {
        "scope_hosts": {
          "type": "list[host]",
          "default": [],
          "description": "Optional list of hostnames to narrow the behavioral analysis after identification."
        },
        "target_cves": {
          "from": {
            "ref": "msrc-blog",
            "kind": "article",
            "observed": "2026-11-09"
          },
          "type": "list[string]",
          "default": [
            "CVE-2015-20001",
            "CVE-2020-36323"
          ],
          "description": "CVE identifiers for known Rust standard library vulnerabilities."
        },
        "rust_modules": {
          "from": {
            "ref": "msrc-blog",
            "kind": "article",
            "observed": "2026-11-09"
          },
          "type": "list[string]",
          "default": [
            "str.rs",
            "unix.rs",
            "map_windows.rs",
            "binaryheap.rs"
          ],
          "description": "Rust source files associated with the reported vulnerabilities."
        },
        "lookback_days": {
          "type": "number",
          "default": "14",
          "description": "Days of history to examine for vulnerabilities and runtime activity."
        }
      },
      "provenance": {
        "authors": [
          {
            "org": "huntbase.io",
            "name": "Huntbase hunt generation"
          }
        ],
        "generated": {
          "by": "huntbase-hunt-generation",
          "from": "https://www.microsoft.com/en-us/security/blog/2026/11/09/forge-lab-uses-agentic-tools-to-identify-memory-safety-issues-in-rust/",
          "gates": [
            "dry-run",
            "lint"
          ],
          "model": "hb_google/gemini-3-flash-preview"
        }
      },
      "references": [
        {
          "url": "https://www.microsoft.com/en-us/security/blog/2026/11/09/forge-lab-uses-agentic-tools-to-identify-memory-safety-issues-in-rust/",
          "name": "FORGE Lab uses agentic tools to identify memory safety issues in Rust"
        }
      ],
      "blind_spots": [
        {
          "id": "static-library-linking",
          "risk": "A software inventory that only tracks top-level packages will miss vulnerable code embedded inside compiled standalone binaries.",
          "owner": "AppSec Team",
          "stage": "vulnerability-inventory",
          "question": "Which applications have statically linked a vulnerable version of the Rust standard library?",
          "requires": "Binary static analysis or SBOM tracking",
          "remediation": "Implement SBOM generation for all internal Rust projects."
        },
        {
          "id": "no-crash-telemetry",
          "risk": "If an application handles its own segmentation faults or restarts silently, the OS-level crash surface will show no signal.",
          "owner": "Infrastructure Team",
          "stage": "application-crash-violation",
          "question": "Did the application crash without generating an operating system error log?",
          "requires": "hb_application_error or OS-level crash reporting",
          "remediation": "Enable application-level crash reporting for critical Rust services."
        },
        {
          "id": "missing-symbols",
          "risk": "The query for specific Rust modules relies on descriptive error messages; if these are stripped, the hunt may fail to identify relevant crashes.",
          "owner": "DevOps",
          "stage": "memory-safety-exploit-trigger",
          "question": "Does the crash message omit the file paths (str.rs, etc.) because symbols were stripped?",
          "requires": "Unstripped binary symbols",
          "remediation": "Maintain unstripped binaries in a symbol server for production triage."
        }
      ]
    },
    "name": "Rust Standard Library Memory Safety Exploitation",
    "description": "This hunt identifies applications exposed to memory-safety flaws in Rust's foundational libraries and detects runtime evidence of their exploitation. It starts by identifying assets with known vulnerable Rust packages or CVEs. If vulnerable hosts exist, the hunt investigates application crashes involving memory corruption (c0000005) associated with Rust source modules, as well as fileless process activity which often follows successful memory exploitation."
  },
  "nodes": [
    {
      "id": "hypothesis",
      "type": "hypothesis",
      "label": "Hypothesis",
      "config": {
        "tags": [],
        "coverage": [
          {
            "stage": "vulnerability-inventory",
            "steps": [
              "identify-vulnerable-rust-assets"
            ],
            "status": "covered"
          },
          {
            "stage": "memory-safety-exploit-trigger",
            "steps": [
              "rust-logic-crashes"
            ],
            "status": "covered"
          },
          {
            "stage": "application-crash-violation",
            "steps": [
              "rust-logic-crashes",
              "rare-fileless-processes"
            ],
            "status": "covered"
          }
        ],
        "rationale": "An adversary is exploiting memory-safety vulnerabilities in the Rust standard library (core and std) to trigger undefined behavior and achieve code execution in public-facing applications.",
        "blind_spots": [
          {
            "id": "static-library-linking",
            "risk": "A software inventory that only tracks top-level packages will miss vulnerable code embedded inside compiled standalone binaries.",
            "owner": "AppSec Team",
            "stage": "vulnerability-inventory",
            "question": "Which applications have statically linked a vulnerable version of the Rust standard library?",
            "requires": "Binary static analysis or SBOM tracking",
            "remediation": "Implement SBOM generation for all internal Rust projects."
          },
          {
            "id": "no-crash-telemetry",
            "risk": "If an application handles its own segmentation faults or restarts silently, the OS-level crash surface will show no signal.",
            "owner": "Infrastructure Team",
            "stage": "application-crash-violation",
            "question": "Did the application crash without generating an operating system error log?",
            "requires": "hb_application_error or OS-level crash reporting",
            "remediation": "Enable application-level crash reporting for critical Rust services."
          },
          {
            "id": "missing-symbols",
            "risk": "The query for specific Rust modules relies on descriptive error messages; if these are stripped, the hunt may fail to identify relevant crashes.",
            "owner": "DevOps",
            "stage": "memory-safety-exploit-trigger",
            "question": "Does the crash message omit the file paths (str.rs, etc.) because symbols were stripped?",
            "requires": "Unstripped binary symbols",
            "remediation": "Maintain unstripped binaries in a symbol server for production triage."
          }
        ],
        "scoping_notes": "The lead query identifies vulnerable device UIDs; the analyst must translate these to hostnames or use the returned inventory data to populate the 'scope_hosts' parameter for the behavioral branches.",
        "beyond_detection": "A detection rule for 'c0000005' crashes is too noisy for production; this hunt filters for specific Rust modules, corroborates with vulnerability status, and pivots to fileless process activity to confirm exploit success."
      }
    },
    {
      "id": "identify-vulnerable-rust-assets",
      "type": "query",
      "label": "Vulnerable Rust library inventory",
      "config": {
        "dsl": "sqlite",
        "role": "scoping",
        "source": "endpoint",
        "content": "SELECT device_uid, cve_uid, affected_package_name, affected_package_version, severity, status FROM hb_vulnerability_finding WHERE (instr(',' || '{{target_cves}}' || ',', ',' || cve_uid || ',') > 0 OR LOWER(affected_package_name) LIKE '%rust%') AND status != 'suppressed'",
        "surface": "hb_vulnerability_finding",
        "description": "Identify hosts running Rust packages affected by the target CVEs or using known vulnerable standard library versions.",
        "expected_signal": "A list of unique device IDs associated with vulnerable Rust installations. Silence indicates no known vulnerable assets are recorded."
      },
      "parents": [
        {
          "id": "hypothesis"
        }
      ],
      "primitive_config": {
        "dsl": "sqlite",
        "role": "scoping",
        "label": "Vulnerable Rust library inventory",
        "reads": [
          "device_uid",
          "cve_uid",
          "affected_package_name",
          "affected_package_version",
          "severity",
          "status"
        ],
        "source": "hb_vulnerability_finding",
        "target": "endpoint",
        "content": "SELECT device_uid, cve_uid, affected_package_name, affected_package_version, severity, status FROM hb_vulnerability_finding WHERE (instr(',' || '{{target_cves}}' || ',', ',' || cve_uid || ',') > 0 OR LOWER(affected_package_name) LIKE '%rust%') AND status != 'suppressed'",
        "silence": "not_evidence_of_absence",
        "expected": "A list of unique device IDs associated with vulnerable Rust installations. Silence indicates no known vulnerable assets are recorded.",
        "verified": "dry-run",
        "verified_at": "2026-11-10"
      }
    },
    {
      "id": "evaluate-vuln-lead",
      "type": "analytic",
      "label": "Evaluate vulnerability lead",
      "config": {
        "cite": "required",
        "tools": [
          "endpoint"
        ],
        "context": [
          "identify-vulnerable-rust-assets"
        ],
        "objective": "Assess the prevalence and severity of vulnerable Rust components across the estate and decide if behavioral analysis is required.",
        "description": "Determine if the exposure to Rust vulnerabilities is significant enough to warrant expensive telemetry queries.",
        "max_iterations": 3,
        "expected_signal": "A recommendation on whether to proceed.",
        "success_criteria": "A recommendation to proceed or end the hunt."
      },
      "parents": [
        {
          "id": "identify-vulnerable-rust-assets"
        }
      ]
    },
    {
      "id": "gate-on-vuln",
      "type": "checkpoint",
      "label": "Gate: Proceed on vulnerable assets",
      "config": {
        "question": "identify-vulnerable-rust-assets.rows > 0",
        "condition": "identify-vulnerable-rust-assets.rows > 0",
        "description": "Halt the hunt if no vulnerable assets are identified, saving resources.",
        "checkpoint_type": "advisory"
      },
      "parents": [
        {
          "id": "evaluate-vuln-lead"
        }
      ]
    },
    {
      "id": "rust-logic-crashes",
      "type": "query",
      "label": "Rust-related memory corruption crashes",
      "config": {
        "dsl": "sqlite",
        "role": "detection-candidate",
        "source": "endpoint",
        "content": "SELECT device_hostname, app_name, exception_code, message, time FROM hb_application_error WHERE exception_code = 'c0000005' AND (LOWER(message) LIKE '%panicked at%' OR LOWER(message) LIKE '%core::%' OR LOWER(message) LIKE '%std::%' OR instr(',' || '{{rust_modules}}' || ',', ',' || LOWER(message) || ',') > 0) AND ('{{scope_hosts}}' = '' OR instr(',' || '{{scope_hosts}}' || ',', ',' || device_hostname || ',') > 0) AND time >= datetime('now', '-{{lookback_days}} days')",
        "surface": "hb_application_error",
        "description": "Identify application crashes with exception c0000005 that reference specific Rust library modules or panic signatures.",
        "expected_signal": "Crash events where the error message includes Rust library internal files or runtime panics. Silence means no such crashes were recorded."
      },
      "parents": [
        {
          "id": "gate-on-vuln",
          "branch": "on_supports"
        }
      ],
      "primitive_config": {
        "dsl": "sqlite",
        "role": "detection-candidate",
        "label": "Rust-related memory corruption crashes",
        "reads": [
          "device_hostname",
          "app_name",
          "exception_code",
          "message",
          "time"
        ],
        "source": "hb_application_error",
        "target": "endpoint",
        "content": "SELECT device_hostname, app_name, exception_code, message, time FROM hb_application_error WHERE exception_code = 'c0000005' AND (LOWER(message) LIKE '%panicked at%' OR LOWER(message) LIKE '%core::%' OR LOWER(message) LIKE '%std::%' OR instr(',' || '{{rust_modules}}' || ',', ',' || LOWER(message) || ',') > 0) AND ('{{scope_hosts}}' = '' OR instr(',' || '{{scope_hosts}}' || ',', ',' || device_hostname || ',') > 0) AND time >= datetime('now', '-{{lookback_days}} days')",
        "silence": "not_evidence_of_absence",
        "expected": "Crash events where the error message includes Rust library internal files or runtime panics. Silence means no such crashes were recorded.",
        "verified": "dry-run",
        "verified_at": "2026-11-10"
      }
    },
    {
      "id": "rare-fileless-processes",
      "type": "query",
      "label": "Rare fileless process activity",
      "config": {
        "dsl": "sqlite",
        "role": "baseline",
        "source": "endpoint",
        "content": "SELECT device_hostname, process_path, process_name, process_cmd_line, COUNT(DISTINCT device_hostname) AS host_count, MIN(time) AS first_seen FROM hb_process_activity WHERE on_disk = 0 AND ('{{scope_hosts}}' = '' OR instr(',' || '{{scope_hosts}}' || ',', ',' || device_hostname || ',') > 0) AND time >= datetime('now', '-{{lookback_days}} days') GROUP BY process_name HAVING host_count <= 3",
        "surface": "hb_process_activity",
        "description": "Identify processes running with no image on disk, which suggests code injection after a memory-safety exploit.",
        "expected_signal": "Injected or fileless processes that are unique to a few hosts. Silence means no fileless activity was found."
      },
      "parents": [
        {
          "id": "gate-on-vuln",
          "branch": "on_supports"
        }
      ],
      "primitive_config": {
        "dsl": "sqlite",
        "role": "baseline",
        "label": "Rare fileless process activity",
        "reads": [
          "device_hostname",
          "process_path",
          "process_name",
          "process_cmd_line",
          "on_disk",
          "time"
        ],
        "source": "hb_process_activity",
        "target": "endpoint",
        "content": "SELECT device_hostname, process_path, process_name, process_cmd_line, COUNT(DISTINCT device_hostname) AS host_count, MIN(time) AS first_seen FROM hb_process_activity WHERE on_disk = 0 AND ('{{scope_hosts}}' = '' OR instr(',' || '{{scope_hosts}}' || ',', ',' || device_hostname || ',') > 0) AND time >= datetime('now', '-{{lookback_days}} days') GROUP BY process_name HAVING host_count <= 3",
        "silence": "not_evidence_of_absence",
        "baseline": {
          "window": "{{lookback_days}}d",
          "compare": "first_seen"
        },
        "expected": "Injected or fileless processes that are unique to a few hosts. Silence means no fileless activity was found.",
        "verified": "dry-run",
        "prevalence": {
          "by": "device_hostname",
          "key": [
            "process_name"
          ],
          "rare_below": 3
        },
        "verified_at": "2026-11-10"
      }
    },
    {
      "id": "final-triage",
      "type": "analytic",
      "label": "Final evidence triage",
      "config": {
        "cite": "required",
        "tools": [
          "endpoint"
        ],
        "context": [
          "evaluate-vuln-lead",
          "rust-logic-crashes",
          "rare-fileless-processes"
        ],
        "objective": "Determine if any single host shows a combination of a Rust-related crash and a rare fileless process, especially if that host was previously flagged as vulnerable.",
        "description": "Synthesize the vulnerability inventory, crash logs, and fileless process behavior to identify active exploitation.",
        "max_iterations": 3,
        "expected_signal": "Per-host verdict citing evidence.",
        "success_criteria": "A per-host verdict of malicious, suspicious, or benign, citing specific rows."
      },
      "parents": [
        {
          "id": "rust-logic-crashes",
          "kind": "merge"
        },
        {
          "id": "rare-fileless-processes",
          "kind": "merge"
        }
      ]
    },
    {
      "id": "final-decision",
      "type": "checkpoint",
      "label": "Route on verdict",
      "config": {
        "fuzzy": true,
        "judge": "hunter",
        "question": "the final-triage verdict is malicious for at least one host",
        "condition": "the final-triage verdict is malicious for at least one host",
        "blind_spot": "no-crash-telemetry",
        "confidence": "high",
        "description": "Direct the response based on the agent's findings.",
        "checkpoint_type": "mandatory"
      },
      "parents": [
        {
          "id": "final-triage"
        }
      ]
    },
    {
      "id": "isolate-target",
      "type": "action",
      "label": "Isolate host",
      "config": {
        "target": "endpoint",
        "description": "Contain a likely compromised host while forensic analysis is performed.",
        "instructions": "Isolate the host from the network and collect a full memory dump for analysis.",
        "action_approval": "required"
      },
      "parents": [
        {
          "id": "final-decision",
          "branch": "on_supports"
        }
      ]
    },
    {
      "id": "analyst-forensic-review",
      "type": "task",
      "label": "Analyst forensic review",
      "config": {
        "assignee": "analyst",
        "description": "Confirm if the identified crashes and fileless processes represent a successful memory-safety exploit.",
        "instructions": "Review the crash dump for the 'c0000005' violation. Look for signs of heap spraying or shellcode. Examine the stack trace to see if the exception occurred during a BinaryHeap operation or a String join as mentioned in the CVEs."
      },
      "parents": [
        {
          "id": "final-decision",
          "branch": "default"
        },
        {
          "id": "final-decision",
          "branch": "on_unavailable"
        },
        {
          "id": "isolate-target"
        }
      ]
    },
    {
      "id": "close-out",
      "type": "task",
      "label": "Close out hunt",
      "config": {
        "assignee": "analyst",
        "description": "Finalize the hunt and record remediation status.",
        "instructions": "Document the findings and update the software inventory to ensure all identified vulnerable Rust binaries are patched. If no activity was found, record the negative result as evidence of security posture."
      },
      "parents": [
        {
          "id": "gate-on-vuln",
          "branch": "on_refutes"
        },
        {
          "id": "final-decision",
          "branch": "on_refutes"
        },
        {
          "id": "analyst-forensic-review"
        }
      ]
    }
  ]
}