{
  "author": "_ext-sigma-7a14fbc3-54d9-4b4d-8700-61eddada04f0[bulk][segment]",
  "cat": "Potentially Suspicious Cabinet File Expansion",
  "detect": {
    "event": {
      "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",
      "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": 10652
    },
    "routing": {
      "arch": 2,
      "did": "",
      "event_id": "e16c7cc8-ba4b-4dca-93c0-18c1f8688294",
      "event_time": 1773901779334,
      "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": 610,
      "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": "f15a5f73cbdd6d1a98bcf2b869bb97d4"
    }
  },
  "detect_id": "62ba7594-8088-43d7-a758-216e69bb97d3",
  "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": 1773901779954,
  "link": "https://app.limacharlie.io/orgs/d3541070-8b0e-4663-8a6a-aa0727aacd36/sensors/ed8f7c3f-3a1a-493e-8fa4-35eb8c30b136/timeline?time=1773901779\u0026selected=f15a5f73cbdd6d1a98bcf2b869bb97d4",
  "namespace": "general",
  "routing": {
    "arch": 2,
    "did": "",
    "event_id": "e16c7cc8-ba4b-4dca-93c0-18c1f8688294",
    "event_time": 1773901779334,
    "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": 610,
    "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": "f15a5f73cbdd6d1a98bcf2b869bb97d4"
  },
  "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": 1773901779000
}

{
  "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": 0.943,
  "false_positive_reason": "Legitimate software maintenance/update behavior by pre-installed OEM utility.",
  "investigation_questions": [
    "Is SRE.exe frequently spawning expand.exe on this host?"
  ],
  "ioc_analysis": "C:\\WINDOWS\\SysWOW64\\expand.exe is a signed Microsoft system binary. The parent process SRE.exe (hash 4209...9f31) is located in the legitimate Dell SupportAssist directory and is also signed. The cabinet file being expanded is part of the Dell Technician Toolkit.",
  "iocs_extracted": [
    "4209038199a68a376fc84137887a18bbeb149f54ad610645f2d585c44a569f31",
    "dfc1709a2988301f7a9d145fb107793e3299ecc85f4b9702523939e35573ab85",
    "C:\\ProgramData\\Dell\\SupportAssist\\TechnicianToolkit\\index.cab"
  ],
  "mitre_techniques": [
    "T1140"
  ],
  "recommended_actions": [
    "Close case as false positive (unanimous AI verdict)",
    "No action required",
    "Consider tuning the detection rule to exclude signed Dell binaries performing cabinet expansion in ProgramData"
  ],
  "risk_score": 10,
  "severity": "low",
  "summary": "**Vote: UNANIMOUS (3/3 -\u003e FALSE POSITIVE)**\n\n### \u264a gemini-cli Analysis (Primary)\n**Verdict:** false_positive | **Confidence:** 0.98\nThe process \u0027expand.exe\u0027 was executed by Dell SupportAssist Agent (SRE.exe) to extract a cabinet file (\u0027index.cab\u0027) from its application data directory. Both parent and child processes are signed binaries and the activity is consistent with standard software maintenance or update operations on Dell systems.\n\n**IOC Analysis:** C:\\WINDOWS\\SysWOW64\\expand.exe is a signed Microsoft system binary. The parent process SRE.exe (hash 4209...9f31) is located in the legitimate Dell SupportAssist directory and is also signed. The cabinet file being expanded is part of the Dell Technician Toolkit.\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 utility located in SysWOW64 and was invoked by Dell SupportAssist Agent to manage technician toolkit files.\n\n**IOC Analysis:** The process path C:\\WINDOWS\\SysWOW64\\expand.exe matches known-good system binary locations. The file is signed (FILE_IS_SIGNED: 1) and the command line shows it expanding a CAB file for Dell SupportAssist, which is a legitimate enterprise support tool.\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 expand.exe is a legitimate Windows utility for cabinet file expansion, and it\u0027s being executed by Dell\u0027s SupportAssist, a trusted application. The context suggests normal operation of a known software package.\n\n**IOC Analysis:** The FILE_PATH C:\\WINDOWS\\SysWOW64\\expand.exe is a legitimate Windows system binary located in the SysWOW64 directory, which is expected for 32-bit tools. The hash indicates a signed binary, consistent with Microsoft-signed utilities. The command line involves expanding a cabinet file from Dell\u0027s SupportAssist, a known legitimate IT management tool, further supporting benign intent.",
  "verdict": "false_positive",
  "voting": {
    "auto_action": "auto_close_fp",
    "mode": "unanimous",
    "total_models": 3,
    "vote_summary": [
      "gemini-cli: false_positive (low, 98% confidence)",
      "qwen3.5:4b: false_positive (low, 95% confidence)",
      "deepseek-r1:8b: false_positive (low, 90% confidence)"
    ],
    "votes": [
      {
        "confidence": 0.98,
        "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"
  }
}