TCP SYN (p0f)

4:51+13:0:1460:mss*29,9:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-06-11 00:21 · last seen 2026-08-08 12:19 · 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

4:51+13:0:1460:mss*29,9:mss,sok,ts,nop,ws:df,id+:0

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleW…

User-Agent claims Windows

TCP SYN initial TTL 51+13 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) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36
Observed TTL	51+13 (observed + path distance → initial)
Claimed OS	Windows
Confidence	medium — repeated co-occurrence, but initial TTL is environmental — capped at medium

medium

2026-07-18

2026-08-08

4:51+13:0:1460:mss*29,9:mss,sok,ts,nop,ws:df,id+:0

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleW…

User-Agent claims Windows

TCP SYN initial TTL 51+13 indicates Unix-like

Full User-Agent	Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36
Observed TTL	51+13 (observed + path distance → initial)
Claimed OS	Windows
Confidence	low — single sighting of an environmental signal

low

2026-06-29

Decomposed attributes

IP version	`4`
Initial TTL	`51+13`
Options length	`0`
MSS	`1460`
Window size	`mss*29`
Window scale	`9`
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
`t13d131100_f57a46bbacb6_ab7e3b40a677` Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.5, go-net/http 1.26.4.The fingerprint page shows the full measured match list. More on the catalog.	10
`t13i191000_9dc949149365_e5728521abd4`	7
`t13d3112h1_e8f1e7e78f70_b26ce05bbdd6` Match?Exact match in Thumbprint's published controlled catalog captures: php-guzzle 8.1.0, php-guzzle 8.0.2, php-guzzle 7.14.2, +6 more.The fingerprint page shows the full measured match list. More on the catalog.	4
`t13d1713h1_ab0a1bf427ad_ecd0401ec68b` Match?Exact match in Thumbprint's published controlled catalog captures: python-httpx 0.28.1.The fingerprint page shows the full measured match list. More on the catalog.	1

HTTP request (JA4H)

fingerprint	co-occurrences
`ge11nn040000_8391bea91fb6_000000000000_000000000000`	9
`pr11nr020000_3ed38b250d3d_000000000000_000000000000`	7
`ge11nn06enus_fb4afd1f380a_000000000000_000000000000`	4
`ge11nr040000_8391bea91fb6_000000000000_000000000000`	1
`ge11nn050000_4c6fd23d173c_000000000000_000000000000`	1

TCP SYN (JA4T)

fingerprint	co-occurrences
`42340_2-4-8-1-3_1460_9`	14

User-Agent

fingerprint	co-occurrences
`Go-http-client/1.1`	9
`-`	7
`Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36`	4
`Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36`	1
`Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.5735.199 Safari/537.36`	1

Country

fingerprint	co-occurrences
`DE` · Germany	9
`NL` · Netherlands	8
`US` · United States	5

Network (ASN)

fingerprint	co-occurrences
`AS212238` · Datacamp Limited	9
`AS211443` · SINO WORLDWIDE TRADING LIMITED	7
`AS14061` · DigitalOcean, LLC	4
`AS215925` · VPSVAULT.HOST LTD	1
`AS397630` · Blazing SEO, LLC	1