{
  "author": "_ext-sigma-7a14fbc3-54d9-4b4d-8700-61eddada04f0[bulk][segment]",
  "cat": "Potentially Suspicious Cabinet File Expansion",
  "detect": {
    "event": {
      "BASE_ADDRESS": 12648448,
      "COMMAND_LINE": "\"C:\\WINDOWS\\SysWOW64\\expand.exe\" -r -F:* \"C:\\ProgramData\\Dell\\SupportAssist\\TechnicianToolkit\\SupportFiles.cab\" \"C:\\ProgramData\\Dell\\SupportAssist\\TechnicianToolkit\\Library\"",
      "FILE_IS_SIGNED": 1,
      "FILE_PATH": "C:\\WINDOWS\\SysWOW64\\expand.exe",
      "HASH": "dfc1709a2988301f7a9d145fb107793e3299ecc85f4b9702523939e35573ab85",
      "MEMORY_USAGE": 8044544,
      "PARENT": {
        "BASE_ADDRESS": 9633792,
        "COMMAND_LINE": "\"C:\\Program Files\\Dell\\SupportAssistAgent\\SRE\\SRE.exe\" \"en\" \"C:\\ProgramData\\Dell\\SupportAssist\\Agent\\Certificate\\SRE\\e231b57f-d97f-475d-bd70-e5b839232e92.pfx\" \"127.0.0.1:10528\" \"5ce2f89a-f6dd-497e-a5d6-38e955aaf176\" \"false\"",
        "FILE_IS_SIGNED": 1,
        "FILE_PATH": "C:\\Program Files\\Dell\\SupportAssistAgent\\SRE\\SRE.exe",
        "HASH": "4209038199a68a376fc84137887a18bbeb149f54ad610645f2d585c44a569f31",
        "MEMORY_USAGE": 4648960,
        "PARENT_ATOM": "7a1843f3f92f80d78b404bd469bb9681",
        "PARENT_PROCESS_ID": 12556,
        "PROCESS_ID": 9256,
        "THIS_ATOM": "6b4a9782c9cf20e12a85883e69bb96e1",
        "THREADS": 4,
        "TIMESTAMP": 1773901536063,
        "USER_NAME": "NT AUTHORITY\\SYSTEM"
      },
      "PARENT_PROCESS_ID": 9256,
      "PROCESS_ID": 12716,
      "THREADS": 1,
      "USER_NAME": "NT AUTHORITY\\SYSTEM"
    },
    "routing": {
      "arch": 2,
      "did": "",
      "event_id": "0f8d5ad9-069c-4906-be19-8ce916df17a5",
      "event_time": 1773901731173,
      "event_type": "NEW_PROCESS",
      "ext_ip": "23.128.32.10",
      "hostname": "desktop-3nfb237",
      "iid": "b2cd59fc-d09d-49e0-a9f2-1fd79ee9c175",
      "int_ip": "192.168.50.40",
      "latency": -26,
      "moduleid": 2,
      "oid": "d3541070-8b0e-4663-8a6a-aa0727aacd36",
      "parent": "6b4a9782c9cf20e12a85883e69bb96e1",
      "plat": 268435456,
      "sid": "ed8f7c3f-3a1a-493e-8fa4-35eb8c30b136",
      "tags": [
        "fusion-soc-alert",
        "fusion-soc-case",
        "fusion-soc-pulled",
        "fusion-soc-triage",
        "fusionsoc-critical",
        "fusionsoc-high",
        "fusionsoc-investigated",
        "qucikbooks",
        "windows",
        "yara_detection_memory"
      ],
      "this": "d9033654546fec6a8bb9bec969bb97a3"
    }
  },
  "detect_id": "02055686-9bed-4e80-8b97-502f69bb97a3",
  "detect_mtd": {
    "author": "Bhabesh Raj, X__Junior (Nextron Systems)",
    "description": "Detects the expansion or decompression of cabinet files from potentially suspicious or uncommon locations, e.g. seen in Iranian MeteorExpress related attacks",
    "falsepositives": [
      "System administrator Usage"
    ],
    "level": "medium",
    "references": [
      "https://labs.sentinelone.com/meteorexpress-mysterious-wiper-paralyzes-iranian-trains-with-epic-troll",
      "https://blog.malwarebytes.com/threat-intelligence/2021/08/new-variant-of-konni-malware-used-in-campaign-targetting-russia/"
    ],
    "tags": [
      "attack.defense-evasion",
      "attack.t1218"
    ]
  },
  "gen_time": 1773901731148,
  "link": "https://app.limacharlie.io/orgs/d3541070-8b0e-4663-8a6a-aa0727aacd36/sensors/ed8f7c3f-3a1a-493e-8fa4-35eb8c30b136/timeline?time=1773901731\u0026selected=d9033654546fec6a8bb9bec969bb97a3",
  "namespace": "general",
  "routing": {
    "arch": 2,
    "did": "",
    "event_id": "0f8d5ad9-069c-4906-be19-8ce916df17a5",
    "event_time": 1773901731173,
    "event_type": "NEW_PROCESS",
    "ext_ip": "23.128.32.10",
    "hostname": "desktop-3nfb237",
    "iid": "b2cd59fc-d09d-49e0-a9f2-1fd79ee9c175",
    "int_ip": "192.168.50.40",
    "latency": -26,
    "moduleid": 2,
    "oid": "d3541070-8b0e-4663-8a6a-aa0727aacd36",
    "parent": "6b4a9782c9cf20e12a85883e69bb96e1",
    "plat": 268435456,
    "sid": "ed8f7c3f-3a1a-493e-8fa4-35eb8c30b136",
    "tags": [
      "fusion-soc-alert",
      "fusion-soc-case",
      "fusion-soc-pulled",
      "fusion-soc-triage",
      "fusionsoc-critical",
      "fusionsoc-high",
      "fusionsoc-investigated",
      "qucikbooks",
      "windows",
      "yara_detection_memory"
    ],
    "this": "d9033654546fec6a8bb9bec969bb97a3"
  },
  "rule_tags": [
    "ext:ext-sigma",
    "attack.defense-evasion",
    "attack.t1218"
  ],
  "source": "d3541070-8b0e-4663-8a6a-aa0727aacd36.b2cd59fc-d09d-49e0-a9f2-1fd79ee9c175.ed8f7c3f-3a1a-493e-8fa4-35eb8c30b136.10000000.2",
  "source_rule": "service.windows_process_creation/proc_creation_win_expand_cabinet_files",
  "ts": 1773901731000
}

{
  "virustotal": {
    "malicious": false,
    "provider": "virustotal",
    "reputation": -11,
    "stats": {
      "confirmed-timeout": 0,
      "failure": 7,
      "harmless": 0,
      "malicious": 0,
      "suspicious": 0,
      "timeout": 2,
      "type-unsupported": 4,
      "undetected": 63
    }
  }
}

{
  "confidence": 0.95,
  "false_positive_reason": "expand.exe is a legitimate Microsoft system utility running from expected location, signed by Microsoft, and invoked by authorized vendor support agent (SRE.exe) under SYSTEM context. Historical analyst feedback confirms this pattern consistently generates false positives.",
  "investigation_questions": [
    "Is Dell SupportAssist installed and authorized on this endpoint?",
    "Has the SYSTEM user account been granted administrative privileges for vendor maintenance?"
  ],
  "ioc_analysis": "expand.exe is a known Microsoft-signed utility located in C:\\WINDOWS\\SysWOW64\\, which matches expected system binary locations. The process is signed (FILE_IS_SIGNED: 1) and spawned by SRE.exe, a legitimate Dell SupportAssist agent component. The command line shows standard cabinet file expansion behavior for vendor support tools.",
  "iocs_extracted": [
    {
      "type": "file_path",
      "value": "C:\\WINDOWS\\SysWOW64\\expand.exe"
    },
    {
      "type": "hash",
      "value": "dfc1709a2988301f7a9d145fb107793e3299ecc85f4b9702523939e35573ab85"
    }
  ],
  "mitre_techniques": [],
  "recommended_actions": [
    "Manual analyst review required \u2014 AI models (majority)",
    "Log as informational event only",
    "No immediate containment required",
    "Verify vendor support tools are authorized on this host"
  ],
  "risk_score": 10,
  "severity": "high",
  "summary": "**Vote: MAJORITY (1/1 -\u003e FALSE POSITIVE)**\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\nThe detection flagged a legitimate Windows system binary (expand.exe) running from its expected SysWOW64 directory to expand a Dell SupportAssist cabinet file under SYSTEM privileges. Historical analyst feedback consistently marks this rule as a false positive for legitimate vendor maintenance tools.\n\n**IOC Analysis:** expand.exe is a known Microsoft-signed utility located in C:\\WINDOWS\\SysWOW64\\, which matches expected system binary locations. The process is signed (FILE_IS_SIGNED: 1) and spawned by SRE.exe, a legitimate Dell SupportAssist agent component. The command line shows standard cabinet file expansion behavior for vendor support tools.\n\n---\n\n### \ud83e\udd16 deepseek-r1:8b Analysis (Secondary)\nFailed or timed out.",
  "verdict": "false_positive",
  "voting": {
    "auto_action": "manual_review",
    "mode": "majority",
    "total_models": 1,
    "vote_summary": [
      "qwen3.5:4b: false_positive (low, 95% confidence)"
    ],
    "votes": [
      {
        "confidence": 0.95,
        "model": "qwen3.5:4b",
        "verdict": "false_positive"
      }
    ],
    "winning_count": 1,
    "winning_verdict": "false_positive"
  }
}