{
  "port": 4003,
  "protocol": "tcp",
  "service": "pxc-splr-ft (IANA registration)",
  "oneLiner": "An IANA name with no public protocol behind it — whatever is listening here picked the port itself.",
  "whatItIs": "IANA registers 4003 as pxc-splr-ft, one of a block of pxc-* names running from 4002 to 4007 that carries no contact, no reference and no published protocol description. There is no well-known software that binds 4003 by default and scanners see it only rarely. In practice a listener here is an application that was told to use a free port, not the registered service.",
  "exposure": {
    "verdict": "careful",
    "note": "The verdict belongs to whatever actually answers — treat an open 4003 as an unidentified service and fingerprint it before deciding."
  },
  "checkCommand": "nc -vz -w 3 TARGET 4003",
  "links": [
    {
      "title": "IANA port registry — 4003 (pxc-splr-ft)",
      "url": "https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=4003",
      "kind": "iana"
    }
  ]
}