TCP SYN (p0f)

4:112+16:0:1280:65535,8:mss,nop,ws,nop,nop,sok:id-:0

first seen 2026-09-27 17:35 · last seen 2026-10-14 05:57 · 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

4:112+16:0:1280:65535,8:mss,nop,ws,nop,nop,sok:id-:0

Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) …

User-Agent claims macOS

TCP SYN initial TTL 112+16 indicates Windows

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 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36
Observed TTL	112+16 (observed + path distance → initial)
Claimed OS	macOS
Confidence	medium — repeated co-occurrence, but initial TTL is environmental — capped at medium

medium

2026-09-27

2026-10-14

Distinct clients per day (last 30 days, peak 1/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	`112+16`
Options length	`0`
MSS	`1280`
Window size	`65535`
Window scale	`8`
Options layout	`mss,nop,ws,nop,nop,sok`
Quirks	`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
`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.	3

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.	3

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.	3

TCP SYN (JA4T)

fingerprint	co-occurrences
`65535_2-1-3-1-1-4_1280_8`	3

User-Agent

fingerprint	co-occurrences
`Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36`	3

Country

fingerprint	co-occurrences
`IN` · India	3

Network (ASN)

fingerprint	co-occurrences
`AS55836` · Reliance Jio Infocomm Limited	3

TLS supported groups

fingerprint	co-occurrences
`0a0a,11ec,001d,0017,0018` Match?Exact match in Thumbprint's published controlled catalog captures: chrome 155.0.8059.40, chrome 156.0.8078.73, chromium 156.0.8078.47, +8 more.The fingerprint page shows the full measured match list. More on the catalog.	1