{
  "author": "_ext-sigma-7a14fbc3-54d9-4b4d-8700-61eddada04f0[bulk][segment]",
  "cat": "Suspicious Msiexec Execute Arbitrary DLL",
  "detect": {
    "event": {
      "BASE_ADDRESS": 140696016846848,
      "COMMAND_LINE": "\"C:\\Windows\\System32\\MsiExec.exe\" /Y \"C:\\Program Files\\Common Files\\Intuit\\Entitlement Client\\v8\\Client\\EntitlementClientBootstrap.dll\"",
      "FILE_IS_SIGNED": 1,
      "FILE_PATH": "C:\\Windows\\System32\\MsiExec.exe",
      "HASH": "677417ba3ad87f73cd95ad30423998c6089e7eef381b309a562cda1eb6fe178e",
      "MEMORY_USAGE": 13414400,
      "PARENT": {
        "BASE_ADDRESS": 140696016846848,
        "COMMAND_LINE": "C:\\WINDOWS\\system32\\msiexec.exe /V",
        "FILE_IS_SIGNED": 1,
        "FILE_PATH": "C:\\WINDOWS\\system32\\msiexec.exe",
        "HASH": "677417ba3ad87f73cd95ad30423998c6089e7eef381b309a562cda1eb6fe178e",
        "MEMORY_USAGE": 57659392,
        "PARENT_ATOM": "33ce860e844f55cab2b62b2c69b0ff35",
        "PARENT_PROCESS_ID": 1680,
        "PROCESS_ID": 38156,
        "THIS_ATOM": "ffb361e9a65ea31762c7273669c2a670",
        "THREADS": 9,
        "TIMESTAMP": 1774364271956,
        "USER_NAME": "NT AUTHORITY\\SYSTEM"
      },
      "PARENT_PROCESS_ID": 38156,
      "PROCESS_ID": 22264,
      "THREADS": 4,
      "USER_NAME": "NT AUTHORITY\\SYSTEM"
    },
    "routing": {
      "arch": 2,
      "did": "",
      "event_id": "f4fd2885-d0cb-4984-aa72-8738dbfa9a37",
      "event_time": 1774364664746,
      "event_type": "NEW_PROCESS",
      "ext_ip": "23.128.32.10",
      "hostname": "desktop-atsepsk",
      "iid": "b2cd59fc-d09d-49e0-a9f2-1fd79ee9c175",
      "int_ip": "192.168.50.200",
      "latency": 1266,
      "moduleid": 2,
      "oid": "d3541070-8b0e-4663-8a6a-aa0727aacd36",
      "parent": "ffb361e9a65ea31762c7273669c2a670",
      "plat": 268435456,
      "sid": "8f3a47be-5629-4c66-921d-17c39ed07e87",
      "tags": [
        "fusion-soc-alert",
        "fusion-soc-case",
        "fusion-soc-pulled",
        "fusion-soc-triage",
        "fusionsoc-critical",
        "fusionsoc-high",
        "fusionsoc-investigated",
        "joys",
        "windows",
        "yara_detection_disk",
        "yara_detection_memory"
      ],
      "this": "bc4e5fe30f6f5eb4e552acf369c2a7f9"
    }
  },
  "detect_id": "62127b55-83e2-4e06-b019-f4e469c2a7fa",
  "detect_mtd": {
    "author": "frack113",
    "description": "Adversaries may abuse msiexec.exe to proxy execution of malicious payloads.\nMsiexec.exe is the command-line utility for the Windows Installer and is thus commonly associated with executing installation packages (.msi)\n",
    "falsepositives": [
      "Legitimate script"
    ],
    "level": "medium",
    "references": [
      "https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/msiexec",
      "https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1218.007/T1218.007.md",
      "https://twitter.com/_st0pp3r_/status/1583914515996897281"
    ],
    "tags": [
      "attack.defense-evasion",
      "attack.t1218.007"
    ]
  },
  "gen_time": 1774364666013,
  "link": "https://app.limacharlie.io/orgs/d3541070-8b0e-4663-8a6a-aa0727aacd36/sensors/8f3a47be-5629-4c66-921d-17c39ed07e87/timeline?time=1774364664\u0026selected=bc4e5fe30f6f5eb4e552acf369c2a7f9",
  "namespace": "general",
  "routing": {
    "arch": 2,
    "did": "",
    "event_id": "f4fd2885-d0cb-4984-aa72-8738dbfa9a37",
    "event_time": 1774364664746,
    "event_type": "NEW_PROCESS",
    "ext_ip": "23.128.32.10",
    "hostname": "desktop-atsepsk",
    "iid": "b2cd59fc-d09d-49e0-a9f2-1fd79ee9c175",
    "int_ip": "192.168.50.200",
    "latency": 1266,
    "moduleid": 2,
    "oid": "d3541070-8b0e-4663-8a6a-aa0727aacd36",
    "parent": "ffb361e9a65ea31762c7273669c2a670",
    "plat": 268435456,
    "sid": "8f3a47be-5629-4c66-921d-17c39ed07e87",
    "tags": [
      "fusion-soc-alert",
      "fusion-soc-case",
      "fusion-soc-pulled",
      "fusion-soc-triage",
      "fusionsoc-critical",
      "fusionsoc-high",
      "fusionsoc-investigated",
      "joys",
      "windows",
      "yara_detection_disk",
      "yara_detection_memory"
    ],
    "this": "bc4e5fe30f6f5eb4e552acf369c2a7f9"
  },
  "rule_tags": [
    "ext:ext-sigma",
    "attack.defense-evasion",
    "attack.t1218.007"
  ],
  "source": "d3541070-8b0e-4663-8a6a-aa0727aacd36.b2cd59fc-d09d-49e0-a9f2-1fd79ee9c175.8f3a47be-5629-4c66-921d-17c39ed07e87.10000000.2",
  "source_rule": "service.windows_process_creation/proc_creation_win_msiexec_execute_dll",
  "ts": 1774364666000
}

{
  "virustotal": {
    "malicious": false,
    "provider": "virustotal",
    "reputation": -3,
    "stats": {
      "confirmed-timeout": 0,
      "failure": 1,
      "harmless": 0,
      "malicious": 0,
      "suspicious": 0,
      "timeout": 0,
      "type-unsupported": 4,
      "undetected": 71
    }
  }
}

{
  "confidence": 0.925,
  "false_positive_reason": "MsiExec.exe is a legitimate Windows system binary used for installing and managing software. The execution of an Entitlement Client DLL is a normal part of Microsoft/Intuit software management workflows.",
  "investigation_questions": [
    "Is there any recent software installation or update activity on this host?",
    "Are there other Intuit-related processes running in the same session?"
  ],
  "ioc_analysis": "The detected IOC (MsiExec.exe) is a standard Windows system binary located in C:\\Windows\\System32\\. It is executing a legitimate DLL for software entitlement management, not malware execution. The process is digitally signed and matches known Microsoft binaries.",
  "iocs_extracted": [
    {
      "type": "file_path",
      "value": "C:\\Windows\\System32\\MsiExec.exe"
    },
    {
      "type": "hash",
      "value": "677417ba3ad87f73cd95ad30423998c6089e7eef381b309a562cda1eb6fe178e"
    }
  ],
  "mitre_techniques": [],
  "recommended_actions": [
    "Manual analyst review required \u2014 AI models (split)",
    "Log the event for audit purposes",
    "No immediate action required - this is a known legitimate process"
  ],
  "risk_score": 15,
  "severity": "high",
  "summary": "**Vote: SPLIT (1/2 -\u003e SUSPICIOUS)**\n\n### \u264a gemini-cli Analysis (Primary)\nFailed or timed out.\n\n---\n\n### \ud83e\udd16 qwen3.5:4b Analysis (Secondary)\n**Verdict:** false_positive | **Confidence:** 0.95\nThis event represents a legitimate Windows Update or maintenance process executing MsiExec to install or update the Intuit Entitlement Client software. The process is running from its expected location and is signed by Microsoft.\n\n**IOC Analysis:** The detected IOC (MsiExec.exe) is a standard Windows system binary located in C:\\Windows\\System32\\. It is executing a legitimate DLL for software entitlement management, not malware execution. The process is digitally signed and matches known Microsoft binaries.\n\n---\n\n### \ud83e\udd16 deepseek-r1:8b Analysis (Secondary)\n**Verdict:** benign | **Confidence:** 0.9\nThe detection event involves MsiExec.exe, a legitimate Windows system binary, executing a DLL from Intuit\u0027s software directory. Given the signed file and context, it is likely part of a standard software installation process.\n\n**IOC Analysis:** MsiExec.exe is a known Windows system binary located in C:\\Windows\\System32, and it is signed, making it unlikely malicious. The command line uses /Y for silent installation, which is common for legitimate software updates. The DLL path points to Intuit\u0027s Entitlement Client, a known legitimate vendor, reducing suspicion.",
  "verdict": "suspicious",
  "voting": {
    "auto_action": "manual_review",
    "mode": "split",
    "total_models": 2,
    "vote_summary": [
      "qwen3.5:4b: false_positive (low, 95% confidence)",
      "deepseek-r1:8b: benign (low, 90% confidence)"
    ],
    "votes": [
      {
        "confidence": 0.95,
        "model": "qwen3.5:4b",
        "verdict": "false_positive"
      },
      {
        "confidence": 0.9,
        "model": "deepseek-r1:8b",
        "verdict": "benign"
      }
    ],
    "winning_count": 1,
    "winning_verdict": "suspicious"
  }
}