TCP SYN (p0f)

6:51+13:0:1440:mss*45,10:mss,sok,ts,nop,ws:flow:0

first seen 2026-07-06 02:36 · last seen 2026-10-04 13:28 · 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

6:51+13:0:1440:mss*45,10:mss,sok,ts,nop,ws:flow: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/153.0.0.0 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

2026-10-04

6:51+13:0:1440:mss*45,10:mss,sok,ts,nop,ws:flow: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 (KHTML, like Gecko) Chrome/146.0.0.0 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

2026-10-04

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	`6`
Initial TTL	`51+13`
Options length	`0`
MSS	`1440`
Window size	`mss*45`
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
`t13d1516h2_8daaf6152771_d8a2da3f94cd` Match?Exact match in Thumbprint's published controlled catalog captures: chromium 149.0.7827.102, chrome 149.0.7827.102, chrome 149.0.7827.156, +25 more.The fingerprint page shows the full measured match list. More on the catalog.	8
`t13d3113h1_e8f1e7e78f70_d339722ba4af`	5
`t13d1617h2_86a278354501_3e9721a6796e`	3
`t13d1516h2_8daaf6152771_02713d6af862` Match?Exact match in Thumbprint's published controlled catalog captures: chromium 131.0.6778.33, chromium 134.0.6998.35, chromium 133.0.6943.16.The fingerprint page shows the full measured match list. More on the catalog.	2
`t12d290700_fc2078a0b8c0_8c06664c3ac5`	2
`t13d5212h1_b262b3658495_8e6e362c5eac` Match?Exact match in Thumbprint's published controlled catalog captures: node-fetch 24.21.0, node-fetch 24.19.0, node-fetch 22.23.1, +9 more.The fingerprint page shows the full measured match list. More on the catalog.	1
`t13d1517h2_8daaf6152771_b1ff8ab2d16f`	1

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, +39 more.The fingerprint page shows the full measured match list. More on the catalog.	8
`ge20nn12enus_60f823d07c94_000000000000_000000000000`	2
`ge11nn040000_bfa5a9b89dd6_000000000000_000000000000`	2
`ge11nn050000_3658ef221638_000000000000_000000000000` Match?Exact match in Thumbprint's published controlled catalog captures: wget 1.21.4, wget 1.25.0, wget 1.21.3.The fingerprint page shows the full measured match list. More on the catalog.	2
`ge11nn040000_8391bea91fb6_000000000000_000000000000`	1
`ge20nr11enus_3901d4197baf_000000000000_000000000000`	1
`ge20nn11enus_3901d4197baf_000000000000_000000000000` Match?Exact match in Thumbprint's published controlled catalog captures: firefox 154.0, firefox 152.0.5, firefox 153.0.1, +3 more.The fingerprint page shows the full measured match list. More on the catalog.	1
`ge20nn13enus_30dc68305204_000000000000_000000000000`	1
`ge20nr13enus_9e2b86631664_000000000000_000000000000`	1
`ge11nn050000_444220f7ef68_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, +60 more.The fingerprint page shows the full measured match list. More on the catalog.	11
`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.	2
`1:65536;2:0;4:131072;5:16384\|12517377\|11:0:0:42\|m,p,a,s`	1

TCP SYN (JA4T)

fingerprint	co-occurrences
`64800_2-4-8-1-3_1440_10`	22

User-Agent

fingerprint	co-occurrences
`Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/153.0.0.0 Safari/537.36`	11
`Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36`	3
`Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36`	3
`Mozilla/5.0 (X11; Linux x86_64; rv:152.0) Gecko/20100101 Firefox/152.0`	3
`Mozilla/5.0 (compatible; MJ12bot/v1.4.8; http://mj12bot.com/)`	2

Country

fingerprint	co-occurrences
`US` · United States	20
`FR` · France	2

Network (ASN)

fingerprint	co-occurrences
`AS16591` · Google Fiber Inc.	17
`AS7922` · Comcast Cable Communications, LLC	3
`AS16276` · OVH SAS	2