TCP SYN (p0f)

4:55+9:0:1332:65535,8:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-07-23 23:46 · last seen 2026-07-23 23:46 · 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

4:55+9:0:1332:65535,8: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 55+9 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/135.0.0.0 Safari/537.36
Observed TTL	55+9 (observed + path distance → initial)
Claimed OS	Windows
Confidence	low — single sighting of an environmental signal

low

2026-07-23

Decomposed attributes

IP version	`4`
Initial TTL	`55+9`
Options length	`0`
MSS	`1332`
Window size	`65535`
Window scale	`8`
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
`t13d871100_c66346c74e42_24695f2957a7`	1

HTTP request (JA4H)

fingerprint	co-occurrences
`ge11nn16enus_7a2bab1d33b1_000000000000_000000000000`	1

TCP SYN (JA4T)

fingerprint	co-occurrences
`65535_2-4-8-1-3_1332_8`	1

User-Agent

fingerprint	co-occurrences
`Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36`	1

Country

fingerprint	co-occurrences
`GB` · United Kingdom	1

Network (ASN)

fingerprint	co-occurrences
`AS60024` · HK CEDOC LIMITED	1