{
  "port": 4004,
  "protocol": "tcp",
  "service": "pxc-roid (IANA registration)",
  "oneLiner": "Registered as pxc-roid and essentially never seen; an open 4004 is an application that chose the number.",
  "whatItIs": "4004 is registered to IANA as pxc-roid, part of the same undocumented pxc-* block as 4002–4007, with no reference, contact or protocol specification attached. No widely deployed software uses it as a default listener. If you find it open, the honest next step is to fingerprint the banner rather than trust the registry name.",
  "exposure": {
    "verdict": "careful",
    "note": "Nothing standard lives here, so exposure depends entirely on the unidentified service that answers."
  },
  "checkCommand": "nc -vz -w 3 TARGET 4004",
  "links": [
    {
      "title": "IANA port registry — 4004 (pxc-roid)",
      "url": "https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=4004",
      "kind": "iana"
    }
  ]
}