{
  "port": 18040,
  "protocol": "tcp",
  "service": "Unassigned",
  "oneLiner": "No IANA registration and no documented default — an unidentified high port that scanners probe by habit.",
  "whatItIs": "18040 is unassigned in the IANA registry and unnamed in Nmap's services database, but it is inside Nmap's default top-1000 TCP set because of observed open-port frequency. The registered ports nearby (18000 biimenu, 18104 radpdf) have no relationship to it. Whatever listens on 18040 chose the number itself.",
  "exposure": {
    "verdict": "careful",
    "note": "Identify the process first. An unknown listener reachable from the internet is worth closing until someone can name it."
  },
  "checkCommand": "sudo lsof -nP -iTCP:18040 -sTCP:LISTEN",
  "links": [
    {
      "title": "IANA Service Name and Transport Protocol Port Number Registry",
      "url": "https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml",
      "kind": "iana"
    },
    {
      "title": "Nmap services frequency database",
      "url": "https://github.com/nmap/nmap/blob/master/nmap-services",
      "kind": "github"
    }
  ]
}