{
  "model_id": "SOC.055",
  "name": "ld.so.preload Modified",
  "description": "/etc/ld.so.preload changed — rootkit technique to inject a shared library into every process.",
  "threshold": 0.9,
  "evaluations": [
    {
      "name": "Write",
      "type": "comparison",
      "left": "event.type",
      "operator": "==",
      "right": "file.critical.write",
      "weight": 4
    },
    {
      "name": "Preload",
      "type": "comparison",
      "left": "event.raw.path",
      "operator": "==",
      "right": "/etc/ld.so.preload",
      "weight": 5
    },
    {
      "name": "Logic",
      "type": "logical",
      "operator": "AND",
      "operands": [
        "Write",
        "Preload"
      ],
      "weight": 5
    }
  ],
  "actions": [
    {
      "type": "emit_alert",
      "reason": "/etc/ld.so.preload modified — IAT hooking / rootkit indicator."
    }
  ],
  "mitre_tactics": [
    "Defense Evasion",
    "Privilege Escalation"
  ],
  "mitre_techniques": [
    "T1574.006",
    "T1055"
  ],
  "severity": "critical",
  "observables": [
    "event.raw.path"
  ]
}