{
  "author": "_ext-sigma-7a14fbc3-54d9-4b4d-8700-61eddada04f0[bulk][segment]",
  "cat": "Potentially Suspicious Cabinet File Expansion",
  "detect": {
    "event": {
      "BASE_ADDRESS": 12058624,
      "COMMAND_LINE": "\"C:\\WINDOWS\\SysWOW64\\expand.exe\" -r -F:* \"C:\\ProgramData\\Dell\\SupportAssist\\TechnicianToolkit\\index.cab\" \"C:\\ProgramData\\Dell\\SupportAssist\\TechnicianToolkit\"",
      "FILE_IS_SIGNED": 1,
      "FILE_PATH": "C:\\WINDOWS\\SysWOW64\\expand.exe",
      "HASH": "dfc1709a2988301f7a9d145fb107793e3299ecc85f4b9702523939e35573ab85",
      "MEMORY_USAGE": 3526656,
      "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": 8544,
      "THREADS": 1,
      "USER_NAME": "NT AUTHORITY\\SYSTEM"
    },
    "routing": {
      "arch": 2,
      "did": "",
      "event_id": "c10a082d-d082-4fc0-8e7c-8cf9daef499b",
      "event_time": 1773901568228,
      "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": 563,
      "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": "474f0377570a779a382dbde769bb9700"
    }
  },
  "detect_id": "18f3a7ab-149a-406f-9b2a-ee8969bb9700",
  "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": 1773901568819,
  "link": "https://app.limacharlie.io/orgs/d3541070-8b0e-4663-8a6a-aa0727aacd36/sensors/ed8f7c3f-3a1a-493e-8fa4-35eb8c30b136/timeline?time=1773901568\u0026selected=474f0377570a779a382dbde769bb9700",
  "namespace": "general",
  "routing": {
    "arch": 2,
    "did": "",
    "event_id": "c10a082d-d082-4fc0-8e7c-8cf9daef499b",
    "event_time": 1773901568228,
    "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": 563,
    "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": "474f0377570a779a382dbde769bb9700"
  },
  "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": 1773901568000
}

{
  "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": "Legitimate maintenance activity by Dell SupportAssist software using native Windows utilities.",
  "investigation_questions": [],
  "ioc_analysis": "Both \u0027expand.exe\u0027 and the parent \u0027SRE.exe\u0027 are located in expected directories and are signed by Microsoft and Dell respectively. The activity is consistent with automated OEM software updates or diagnostic tool operations.",
  "iocs_extracted": [
    "C:\\WINDOWS\\SysWOW64\\expand.exe",
    "C:\\Program Files\\Dell\\SupportAssistAgent\\SRE\\SRE.exe",
    "dfc1709a2988301f7a9d145fb107793e3299ecc85f4b9702523939e35573ab85",
    "4209038199a68a376fc84137887a18bbeb149f54ad610645f2d585c44a569f31"
  ],
  "mitre_techniques": [
    "T1059"
  ],
  "recommended_actions": [
    "Close case as false positive (unanimous AI verdict)",
    "Whiltelist expand.exe when spawned by Dell SupportAssist binaries in Program Files",
    "Close case as False Positive"
  ],
  "risk_score": 7,
  "severity": "low",
  "summary": "**Vote: UNANIMOUS (3/3 -\u003e FALSE POSITIVE)**\n\n### \u264a gemini-cli Analysis (Primary)\n**Verdict:** false_positive | **Confidence:** 1.0\nThe detection triggered on a legitimate use of the Windows \u0027expand.exe\u0027 utility by Dell SupportAssist. The parent process \u0027SRE.exe\u0027 is a signed Dell binary performing standard maintenance by extracting cabinet files within its ProgramData directory.\n\n**IOC Analysis:** Both \u0027expand.exe\u0027 and the parent \u0027SRE.exe\u0027 are located in expected directories and are signed by Microsoft and Dell respectively. The activity is consistent with automated OEM software updates or diagnostic tool operations.\n\n---\n\n### \ud83e\udd16 qwen3.5:4b Analysis (Secondary)\n**Verdict:** false_positive | **Confidence:** 0.95\nThis detection is a false positive because expand.exe is a legitimate Windows system binary located in the expected SysWOW64 directory and is Microsoft-signed. The process was spawned by Dell SupportAssist Agent as part of normal enterprise support tool functionality.\n\n**IOC Analysis:** The process path C:\\WINDOWS\\SysWOW64\\expand.exe matches known-good Windows system binary locations. The file is signed (FILE_IS_SIGNED: 1) and the command line shows it expanding a Dell SupportAssist cabinet file, which is consistent with legitimate enterprise support software behavior.\n\n---\n\n### \ud83e\udd16 deepseek-r1:8b Analysis (Secondary)\n**Verdict:** false_positive | **Confidence:** 0.9\nThe detection is likely a false positive as the process is part of the legitimate Dell SupportAssist toolkit, with a signed executable and benign parent process, despite the non-standard location of expand.exe.\n\n**IOC Analysis:** FILE_PATH: C:\\WINDOWS\\SysWOW64\\expand.exe is not a standard Windows binary location, but it is signed, reducing suspicion. HASH: dfc1709a2988301f7a9d145fb107793e3299ecc85f4b9702523939e35573ab85 is signed, indicating it could be from a legitimate vendor. COMMAND_LINE: Expands a CAB file from Dell SupportAssist, which is a legitimate application for system maintenance.",
  "verdict": "false_positive",
  "voting": {
    "auto_action": "auto_close_fp",
    "mode": "unanimous",
    "total_models": 3,
    "vote_summary": [
      "gemini-cli: false_positive (low, 100% confidence)",
      "qwen3.5:4b: false_positive (low, 95% confidence)",
      "deepseek-r1:8b: false_positive (low, 90% confidence)"
    ],
    "votes": [
      {
        "confidence": 1.0,
        "model": "gemini-cli",
        "verdict": "false_positive"
      },
      {
        "confidence": 0.95,
        "model": "qwen3.5:4b",
        "verdict": "false_positive"
      },
      {
        "confidence": 0.9,
        "model": "deepseek-r1:8b",
        "verdict": "false_positive"
      }
    ],
    "winning_count": 3,
    "winning_verdict": "false_positive"
  }
}