{
  "model_id": "SOC.031",
  "name": "Base64 Decode And Execute",
  "description": "Process cmdline contains 'base64 -d' piped to an interpreter — common obfuscation technique.",
  "threshold": 0.75,
  "evaluations": [
    {
      "name": "Proc",
      "type": "comparison",
      "left": "event.type",
      "operator": "==",
      "right": "process.longlived",
      "weight": 2
    },
    {
      "name": "B64",
      "type": "comparison",
      "left": "event.raw.cmdline",
      "operator": "LIKE",
      "right": "%base64 -d%",
      "weight": 4
    },
    {
      "name": "Pipe",
      "type": "comparison",
      "left": "event.raw.cmdline",
      "operator": "LIKE",
      "right": "%|%",
      "weight": 3
    },
    {
      "name": "Logic",
      "type": "logical",
      "operator": "AND",
      "operands": [
        "Proc",
        "B64",
        "Pipe"
      ],
      "weight": 5
    }
  ],
  "actions": [
    {
      "type": "emit_alert",
      "reason": "Base64 decode + execute pattern — likely obfuscated payload."
    }
  ],
  "mitre_tactics": [
    "Execution",
    "Defense Evasion"
  ],
  "mitre_techniques": [
    "T1059",
    "T1140"
  ],
  "severity": "high",
  "observables": [
    "event.actor.exe",
    "event.actor.pid"
  ]
}