{
  "author": "_ext-sigma-7a14fbc3-54d9-4b4d-8700-61eddada04f0[bulk][segment]",
  "cat": "Directory Removal Via Rmdir",
  "detect": {
    "event": {
      "COMMAND_LINE": "\"C:\\Windows\\System32\\cmd.exe\" /q /c rmdir /s /q \"C:\\Users\\pjhow\\AppData\\Local\\Microsoft\\OneDrive\\26.026.0209.0004\"",
      "FILE_IS_SIGNED": 1,
      "FILE_PATH": "C:\\Windows\\System32\\cmd.exe",
      "HASH": "f682aadda9deb654885ae17909380a25f7cb1a43ac0934ac425ee8de4924c7f3",
      "PARENT": {
        "BASE_ADDRESS": 140697881149440,
        "COMMAND_LINE": "C:\\WINDOWS\\Explorer.EXE",
        "FILE_IS_SIGNED": 1,
        "FILE_PATH": "C:\\WINDOWS\\Explorer.EXE",
        "HASH": "6d560ce5e75149dffe1b67f0a9f1a0717c9996d50ef2dbf3349b251b64c3a195",
        "MEMORY_USAGE": 34713600,
        "PARENT_ATOM": "b4c888978aa0174f6ca942a969c30db5",
        "PARENT_PROCESS_ID": 3324,
        "PROCESS_ID": 1984,
        "THIS_ATOM": "95030fcbb1b0f80539943cfe69c30db5",
        "THREADS": 11,
        "TIMESTAMP": 1774390708232,
        "USER_NAME": "WIN-91LCCQ536B4\\pjhow"
      },
      "PARENT_PROCESS_ID": 1984,
      "PROCESS_ID": 10260
    },
    "routing": {
      "arch": 2,
      "did": "",
      "event_id": "26ec66aa-7697-43f9-a82e-51730d6ae47d",
      "event_time": 1774390753800,
      "event_type": "NEW_PROCESS",
      "ext_ip": "23.128.32.10",
      "hostname": "win-91lccq536b4",
      "iid": "b2cd59fc-d09d-49e0-a9f2-1fd79ee9c175",
      "int_ip": "192.168.50.170",
      "latency": 2084,
      "moduleid": 2,
      "oid": "d3541070-8b0e-4663-8a6a-aa0727aacd36",
      "parent": "95030fcbb1b0f80539943cfe69c30db5",
      "plat": 268435456,
      "sid": "f8e98d83-79d8-4ff7-9fe1-7c507dad89e4",
      "tags": [
        "frontdesk",
        "fusion-soc-alert",
        "fusion-soc-case",
        "fusion-soc-pulled",
        "fusion-soc-triage",
        "fusionsoc-critical",
        "fusionsoc-investigated",
        "windows",
        "yara_detection_memory"
      ],
      "this": "26af88dbc68c12c9aed2421b69c30de3"
    }
  },
  "detect_id": "3b1af3f3-4f06-4c91-9074-21d769c30de3",
  "detect_mtd": {
    "author": "frack113",
    "description": "Detects execution of the builtin \"rmdir\" command in order to delete directories.\nAdversaries may delete files left behind by the actions of their intrusion activity.\nMalware, tools, or other non-native files dropped or created on a system by an adversary may leave traces to indicate to what was done within a network and how.\nRemoval of these files can occur during an intrusion, or as part of a post-intrusion process to minimize the adversary\u0027s footprint.\n",
    "falsepositives": [
      "Unknown"
    ],
    "level": "low",
    "references": [
      "https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1070.004/T1070.004.md",
      "https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/erase"
    ],
    "tags": [
      "attack.defense-evasion",
      "attack.t1070.004"
    ]
  },
  "gen_time": 1774390755886,
  "link": "https://app.limacharlie.io/orgs/d3541070-8b0e-4663-8a6a-aa0727aacd36/sensors/f8e98d83-79d8-4ff7-9fe1-7c507dad89e4/timeline?time=1774390753\u0026selected=26af88dbc68c12c9aed2421b69c30de3",
  "namespace": "general",
  "routing": {
    "arch": 2,
    "did": "",
    "event_id": "26ec66aa-7697-43f9-a82e-51730d6ae47d",
    "event_time": 1774390753800,
    "event_type": "NEW_PROCESS",
    "ext_ip": "23.128.32.10",
    "hostname": "win-91lccq536b4",
    "iid": "b2cd59fc-d09d-49e0-a9f2-1fd79ee9c175",
    "int_ip": "192.168.50.170",
    "latency": 2084,
    "moduleid": 2,
    "oid": "d3541070-8b0e-4663-8a6a-aa0727aacd36",
    "parent": "95030fcbb1b0f80539943cfe69c30db5",
    "plat": 268435456,
    "sid": "f8e98d83-79d8-4ff7-9fe1-7c507dad89e4",
    "tags": [
      "frontdesk",
      "fusion-soc-alert",
      "fusion-soc-case",
      "fusion-soc-pulled",
      "fusion-soc-triage",
      "fusionsoc-critical",
      "fusionsoc-investigated",
      "windows",
      "yara_detection_memory"
    ],
    "this": "26af88dbc68c12c9aed2421b69c30de3"
  },
  "rule_tags": [
    "ext:ext-sigma",
    "attack.defense-evasion",
    "attack.t1070.004"
  ],
  "source": "d3541070-8b0e-4663-8a6a-aa0727aacd36.b2cd59fc-d09d-49e0-a9f2-1fd79ee9c175.f8e98d83-79d8-4ff7-9fe1-7c507dad89e4.10000000.2",
  "source_rule": "service.windows_process_creation/proc_creation_win_cmd_rmdir_execution",
  "ts": 1774390756000
}

{
  "virustotal": {
    "malicious": false,
    "provider": "virustotal",
    "reputation": 1,
    "stats": {
      "confirmed-timeout": 0,
      "failure": 0,
      "harmless": 0,
      "malicious": 0,
      "suspicious": 0,
      "timeout": 0,
      "type-unsupported": 4,
      "undetected": 72
    }
  }
}

{
  "confidence": 0.95,
  "false_positive_reason": "legitimate_system_administrative_activity",
  "investigation_questions": [
    "Is OneDrive currently updating on this host?",
    "Are there other instances of this command across the fleet during update windows?"
  ],
  "ioc_analysis": "The process C:\\Windows\\System32\\cmd.exe is a legitimate Windows binary. The command line targets a specific versioned folder within the user\u0027s Microsoft OneDrive directory (26.026.0209.0004), which is consistent with routine application maintenance.",
  "iocs_extracted": [
    "C:\\Windows\\System32\\cmd.exe",
    "C:\\Users\\pjhow\\AppData\\Local\\Microsoft\\OneDrive\\26.026.0209.0004"
  ],
  "mitre_techniques": [
    "T1070.004"
  ],
  "recommended_actions": [
    "Manual analyst review required \u2014 AI models (majority)",
    "No action required",
    "Consider tuning the rule to exclude common application cleanup paths like OneDrive AppData"
  ],
  "risk_score": 5,
  "severity": "high",
  "summary": "**Vote: MAJORITY (1/1 -\u003e FALSE POSITIVE)**\n\n### \u264a gemini-cli Analysis (Primary)\n**Verdict:** false_positive | **Confidence:** 0.95\nThe detection triggered on a \u0027rmdir\u0027 command targeting a OneDrive versioned directory in AppData. This is standard behavior for the Microsoft OneDrive client during updates or maintenance to clean up old version files.\n\n**IOC Analysis:** The process C:\\Windows\\System32\\cmd.exe is a legitimate Windows binary. The command line targets a specific versioned folder within the user\u0027s Microsoft OneDrive directory (26.026.0209.0004), which is consistent with routine application maintenance.\n\n---\n\n### \ud83e\udd16 qwen3.5:4b Analysis (Secondary)\nFailed or timed out.\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": [
      "gemini-cli: false_positive (low, 95% confidence)"
    ],
    "votes": [
      {
        "confidence": 0.95,
        "model": "gemini-cli",
        "verdict": "false_positive"
      }
    ],
    "winning_count": 1,
    "winning_verdict": "false_positive"
  }
}