{
  "model_id": "SOC.091",
  "name": "Service Stopped Unexpectedly",
  "description": "Critical service (sshd, nginx, postgres, docker) stopped — could be attacker disabling defences or an outage.",
  "threshold": 0.7,
  "evaluations": [
    {
      "name": "Systemctl",
      "type": "comparison",
      "left": "event.raw.comm",
      "operator": "==",
      "right": "systemctl",
      "weight": 3
    },
    {
      "name": "Stop",
      "type": "comparison",
      "left": "event.raw.cmdline",
      "operator": "LIKE",
      "right": "%stop%",
      "weight": 4
    },
    {
      "name": "CriticalSvc",
      "type": "comparison",
      "left": "event.raw.cmdline",
      "operator": "IN",
      "right": [
        "sshd",
        "nginx",
        "postgres",
        "docker",
        "auditd",
        "fail2ban"
      ],
      "weight": 5
    },
    {
      "name": "Logic",
      "type": "logical",
      "operator": "AND",
      "operands": [
        "Systemctl",
        "Stop",
        "CriticalSvc"
      ],
      "weight": 5
    }
  ],
  "actions": [
    {
      "type": "emit_alert",
      "reason": "Critical service stopped: {event.raw.cmdline}."
    }
  ],
  "mitre_tactics": [
    "Impact",
    "Defense Evasion"
  ],
  "mitre_techniques": [
    "T1529",
    "T1562"
  ],
  "severity": "high",
  "observables": [
    "event.actor.user"
  ]
}