408
Summary
- // typical exposure
- Anomalous (rarely legitimately open) — Prm-sm is an obsolete academic Prospero component with no documented modern deployment and the lowest measured open-port frequency in this batch, so a responsive 408/tcp is unexpected and should be treated as anomalous rather than routine service traffic.
- // analyst note
- essentially unused legacy academic protocol, now numerically confirmed as the rarest port in this batch — treat an open 408/tcp as unexpected and worth investigating rather than assuming a benign service.
- // if you see it open
- No confirmed CVE or documented malware family is tied to 408/tcp. auditmypc.com's verdict for this port is a confirmed negative ('Virus/Trojan: No'); its generic template sentence about ports being 'flagged' is site-wide boilerplate printed over that negative verdict, not a threat signal. Because Prospero/prm-sm has no documented modern deployment, an open 408/tcp is itself an anomaly worth investigating, and its measured open-port frequency (0.000013) is the lowest in this batch.
About port 408/tcp.
Port 408/tcp carries prm-sm, a legacy component of the 1990s Prospero distributed resource-management/file-discovery system; it has no documented modern deployment, so it should not be expected on the public internet or on any current network.
Prospero was an early-1990s distributed file/resource-discovery system built at USC/ISI. The prm-sm service name tracks the resource manager's "system manager" role within that architecture, but the project saw little deployment outside academic and research settings and has no meaningful footprint on today's internet.
The IANA registry entry carries no assignee name and no RFC reference for this port — both fields are blank in the registry itself, not omitted by this write-up. A parallel entry for 408/udp exists in the same registry row block, indicating the dual TCP/UDP registration pattern common to older service-name assignments.
Measured open-port frequency for 408/tcp is 0.000013 in the nmap-services dataset bundled at this site's own tooling — the lowest figure seen across this batch of ports, which numerically confirms the "essentially unused" framing rather than leaving it as an absence of data. No specific software was identified as commonly generating traffic on this port.
- IANA assignment
prm-sm— "Prospero Resource Manager Sys. Man."; reference (blank — no RFC cited in IANA registry); assignee blank; dual-registered 408/tcp + 408/udp [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry line 809-810; IANA Service Name and Transport Protocol Port Number Registry- Range class
- well-known (0–1023) [Confirmed]
- Prevalence
- nmap-services open-frequency 408/tcp = 0.000013 — the lowest figure in this batch [Confirmed] — this site's own tooling
- Related ports
- 408/udp (
prm-sm, same IANA row; nmap-services frequency 0.000445) [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry line 809-810; this site's own tooling
Primary use
legacy System Manager component of the Prospero distributed resource-management/file-discovery system (USC/ISI, early 1990s); no evidence of significant modern deployment
Other/unofficial uses
none documented in auditmypc.com's port profile — confirmed blank there, not merely unresearched
Security implications
no confirmed CVE or documented malware family; auditmypc.com's verdict for this port is a confirmed negative ("Virus/Trojan: No") despite generic template wording
Typically seen on
no known modern hosts beyond legacy/historical Prospero deployments; an open instance elsewhere is an anomaly [Likely]
- Analyst note
- essentially unused legacy academic protocol, now numerically confirmed as the rarest port in this batch — treat an open 408/tcp as unexpected and worth investigating rather than assuming a benign service.
About port 408/udp.
Port 408/udp is registered with IANA to prm-sm ("Prospero Resource Manager Sys. Man."), a legacy early-1990s assignment tied to the Prospero distributed resource/file-location protocol from USC's Information Sciences Institute; it carries no meaningful production traffic today, so it does not belong on the public internet and a live listener here should be treated as unusual rather than a normal service.
The IANA registry entry leaves the Reference, Assignee, and Contact fields blank, meaning no RFC or named registrant is cited for this specific port number. The corresponding TCP port, 408/tcp, is dual-registered to the same prm-sm service name — a common pattern for assignments made before ports were reliably split into TCP-only or UDP-only registrations.
Prospero itself was a distributed file/resource-naming system built at USC/ISI in the early 1990s; it predates modern service-discovery approaches and saw limited adoption outside research settings. No dedicated RFC documents this specific port assignment, and neither the IANA registry entry nor the auditmypc.com port profile records any ongoing production use — a confirmed blank in both sources, not merely an unexamined one.
- IANA assignment
prm-sm— "Prospero Resource Manager Sys. Man."; reference (blank — no RFC cited); assignee/contact blank; dual-registered 408/tcp + 408/udp [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry lines 809-810- Range class
- well-known (0–1023)
- Prevalence
- 0.000445 nmap-services open-frequency figure — roughly 34x the paired 408/tcp figure of 0.000013 [Confirmed] — this site's own tooling
- Related ports
- 408/tcp (dual-registered to the same
prm-smservice)
Primary use
legacy IANA assignment tied to the Prospero distributed resource/file-location protocol (USC/ISI, early 1990s); no meaningful production usage documented today
Other/unofficial uses
none credibly documented; a claimed UPnP association was investigated and excluded as unreliable (UPnP/SSDP uses UDP 1900) [Unknown]
Security implications
no known malware association; AuditMyPC does not flag UDP 408 as virus/trojan-associated; essentially never seen in legitimate production traffic today
Typically seen on
legacy/research Prospero-related deployments if ever seen at all; otherwise an anomaly [Unknown]
- Analyst note
- an open 408/udp is statistically rare and has no documented legitimate modern use case — treat as anomalous and investigate.
Service assignments.
| Name | Protocol | Description | Open frequency |
|---|---|---|---|
| prm-sm | UDP | Prospero Resource Manager Sys. Man. | 0.04% |
| prm-sm | TCP | Prospero Resource Manager Sys. Man. | 0.00% |
Service assignments from the IANA Service Name and Transport Protocol Port Number Registry, with open-frequency data from nmap-services.