No registered service — it is on scans only because Nmap probes it by default.
52673 sits in the Dynamic/Private range (49152-65535), which RFC 6335 sets aside for local and ephemeral use and where IANA assigns nothing. Nmap's nmap-services file lists it as "unknown" with an observed-open frequency of 0.000228, which is enough to keep it inside the default top-1000 TCP set that a bare nmap TARGET scans. No public service database names an application here — SANS ISC also shows the service field empty. In practice a hit is either an ephemeral client socket caught mid-connection or a program that was told to bind a high port.
Expose with care
You cannot rate a port you cannot name. Identify the owning process locally before deciding anything; an unidentified listener on a public IP should be closed until it is identified.
$ sudo lsof -nP -iTCP:52673 -sTCP:LISTENSeen this on your network? Beige Box scans your Wi-Fi and shows every open port on every device — and its Ports tool links straight back here.
Get Beige Box →also available as JSON · Markdown
Corrections or a missing port? Reply @rimrocksystems.