TCP SYN (p0f)

6:54+10:0:1439:65535,10:mss,sok,ts,nop,ws:flow:0

first seen 2026-09-16 17:46 · last seen 2026-09-16 17:57 · 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

6:54+10:0:1439:65535,10:mss,sok,ts,nop,ws:flow:0

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:155…

User-Agent claims Windows

TCP SYN initial TTL 54+10 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:155.0) Gecko/20100101 Firefox/155.0
Observed TTL	54+10 (observed + path distance → initial)
Claimed OS	Windows
Confidence	low — single sighting of an environmental signal

low

2026-09-16

Decomposed attributes

IP version	`6`
Initial TTL	`54+10`
Options length	`0`
MSS	`1439`
Window size	`65535`
Window scale	`10`
Options layout	`mss,sok,ts,nop,ws`
Quirks	`flow`
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
`t13d2013h2_a09f3c656075_7f0f34a4126d` Match?Exact match in Thumbprint's published controlled catalog captures: safari 26.5.2, safari 26.6.2, safari 26.4, +2 more.The fingerprint page shows the full measured match list. More on the catalog.	2

HTTP request (JA4H)

fingerprint	co-occurrences
`ge20nn13enus_0c2c1d640f3e_000000000000_000000000000` Match?Exact match in Thumbprint's published controlled catalog captures: chrome 151.0.7922.137, chrome 151.0.7922.170, chrome 151.0.7922.108, +36 more.The fingerprint page shows the full measured match list. More on the catalog.	1
`ge20nn11ruru_3901d4197baf_000000000000_000000000000`	1

HTTP/2 frames (Akamai)

fingerprint	co-occurrences
`1:65536;2:0;4:6291456;6:262144\|15663105\|1:1:0:256\|m,a,s,p` Match?Exact match in Thumbprint's published controlled catalog captures: chromium 131.0.6778.33, chromium 151.0.7922.34, chrome 151.0.7922.137, +57 more.The fingerprint page shows the full measured match list. More on the catalog.	1
`1:65536;2:0;4:131072;5:16384\|12517377\|3:0:0:42\|m,p,a,s` Match?Exact match in Thumbprint's published controlled catalog captures: firefox 154.0, firefox 152.0.5, firefox 152.0.1, +3 more.The fingerprint page shows the full measured match list. More on the catalog.	1

TCP SYN (JA4T)

fingerprint	co-occurrences
`65535_2-4-8-1-3_1439_10`	2

User-Agent

fingerprint	co-occurrences
`Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/152.0.0.0 Mobile Safari/537.36`	1
`Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:155.0) Gecko/20100101 Firefox/155.0`	1

Country

fingerprint	co-occurrences
`RU` · Russia	2

Network (ASN)

fingerprint	co-occurrences
`AS12389` · PJSC Rostelecom	2