{
  "model_id": "SOC.098",
  "name": "Crontab Modified Directly",
  "description": "/etc/crontab (system-wide crontab) modified — affects every user's scheduled jobs.",
  "threshold": 0.8,
  "evaluations": [
    {
      "name": "Write",
      "type": "comparison",
      "left": "event.type",
      "operator": "==",
      "right": "file.critical.write",
      "weight": 4
    },
    {
      "name": "Crontab",
      "type": "comparison",
      "left": "event.raw.path",
      "operator": "==",
      "right": "/etc/crontab",
      "weight": 5
    },
    {
      "name": "Logic",
      "type": "logical",
      "operator": "AND",
      "operands": [
        "Write",
        "Crontab"
      ],
      "weight": 5
    }
  ],
  "actions": [
    {
      "type": "emit_alert",
      "reason": "/etc/crontab modified — system-wide schedule change."
    }
  ],
  "mitre_tactics": [
    "Persistence"
  ],
  "mitre_techniques": [
    "T1053.003"
  ],
  "severity": "high",
  "observables": [
    "event.raw.path"
  ]
}