TCP SYN (p0f)

4:53+11:0:1460:mss*29,10:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-06-30 17:41 · last seen 2026-09-15 05:15 · JSON

Inconsistencies

User-Agents observed with this fingerprint that contradict what it proves at the wire. all inconsistencies →

fingerprint User-Agent claims wire shows confidence seen first seen last seen

4:53+11:0:1460:mss*29,10:mss,sok,ts,nop,ws:df,id+:0

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:154…

User-Agent claims Windows

TCP SYN initial TTL 53+11 indicates Unix-like

The initial TTL is set by the sending kernel (64 on Unix-like systems, 128 on Windows) and survives NAT. But VPNs, proxies and tunnels legitimately replace the sending stack, so this check never exceeds medium confidence.

Full User-Agent	Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:154.0) Gecko/20100101 Firefox/154.0
Observed TTL	53+11 (observed + path distance → initial)
Claimed OS	Windows
Confidence	low — single sighting of an environmental signal

low

2026-08-26

Last 7 days (2 observations)

Distinct clients per day (last 30 days, peak 2/day)

Distinct clients are counted by IP-hash per complete UTC day — unlike observation counts this is insensitive to one chatty client, but NAT merges clients and address rotation splits them.

Decomposed attributes

IP version	`4`
Initial TTL	`53+11`
Options length	`0`
MSS	`1460`
Window size	`mss*29`
Window scale	`10`
Options layout	`mss,sok,ts,nop,ws`
Quirks	`df,id+`
Payload class	`0`

Co-observed signals

Signals from other families seen in the same observation. A fingerprint spread thinly across many lower-layer signatures is a classic inconsistency signal.

TLS ClientHello (JA4)

fingerprint	co-occurrences
`t13i1909h2_9dc949149365_97f8aa674fd9`	38
`t13d1716h2_5b57614c22b0_ca3c9f312770`	1

HTTP request (JA4H)

fingerprint	co-occurrences
`ge20nr030000_80b089f68b8e_000000000000_000000000000`	25
`ge20nr030000_ff50983941c1_000000000000_000000000000`	13
`ge20nr10enus_b3034183f430_000000000000_000000000000` Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 154.0, +21 more.The fingerprint page shows the full measured match list. More on the catalog.	1

HTTP/2 frames (Akamai)

fingerprint	co-occurrences
`2:0;4:4194304;5:16384;6:10485760\|1073741824\|0\|a,m,p,s` Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.8, go-net/http 1.26.7, +6 more.The fingerprint page shows the full measured match list. More on the catalog.	38
`1:65536;2:0;4:131072;5:16384\|12517377\|3:0:0:22\|m,p,a,s` Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 154.0, +25 more.The fingerprint page shows the full measured match list. More on the catalog.	1

TCP SYN (JA4T)

fingerprint	co-occurrences
`42340_2-4-8-1-3_1460_10`	39

User-Agent

fingerprint	co-occurrences
`Mozilla/5.0 (compatible; CyberConvoyScout/1.0; +https://scout.cyberconvoy.co)`	38
`Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:154.0) Gecko/20100101 Firefox/154.0`	1

Country

fingerprint	co-occurrences
`GB` · United Kingdom	20
`US` · United States	11
`FR` · France	8

Network (ASN)

fingerprint	co-occurrences
`AS20473` · The Constant Company, LLC	39