TCP SYN (p0f)

4:112+16:0:1420:8192,2:mss,nop,ws,nop,nop,sok:df,id+:0

first seen 2026-08-29 22:20 · last seen 2026-10-23 22:06 · 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+16:0:1420:8192,2:mss,nop,ws,nop,nop,sok:df,id+:0

Mozilla/5.0 (iPhone; CPU iPhone OS 18_1 like Mac…

User-Agent claims iOS

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 (iPhone; CPU iPhone OS 18_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.1 Mobile/15E148 Safari/604.1
Observed TTL	112+16 (observed + path distance → initial)
Claimed OS	iOS
Confidence	low — single sighting of an environmental signal

low

2026-08-29

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	`1420`
Window size	`8192`
Window scale	`2`
Options layout	`mss,nop,ws,nop,nop,sok`
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
`t13d2913h1_723694b0fccc_5671b5df5029`	2
`t13d3013h2_1d37bd780c83_8537cf56674e`	1

HTTP request (JA4H)

fingerprint	co-occurrences
`ge20nn030000_bf75ddd0bb29_000000000000_000000000000`	1
`ge11nr11nlbe_b350a6a7c155_000000000000_000000000000`	1
`ge11nr11nlbe_835281d8e5d9_000000000000_000000000000`	1

HTTP/2 frames (Akamai)

fingerprint	co-occurrences
`3:100;4:65536;2:0\|1048510465\|0\|m,s,a,p` Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.13.0, curl 8.18.0, curl 8.21.0, +8 more.The fingerprint page shows the full measured match list. More on the catalog.	1

TCP SYN (JA4T)

fingerprint	co-occurrences
`8192_2-1-3-1-1-4_1420_2`	3

User-Agent

fingerprint	co-occurrences
`Mozilla/5.0 (iPhone; CPU iPhone OS 18_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.1 Mobile/15E148 Safari/604.1`	2
`curl/8.14.1`	1

Country

fingerprint	co-occurrences
`BE` · Belgium	2
`JP` · Japan	1

Network (ASN)

fingerprint	co-occurrences
`AS6848` · Telenet BV	2
`AS17676` · SoftBank Corp.	1

TLS supported groups

fingerprint	co-occurrences
`11ec,001d,0017,001e,0018,0019,0100,0101` Match?Exact match in Thumbprint's published controlled catalog captures: node-fetch 24.22.1, python-httpx 0.28.1, python-requests 2.34.2, +2 more.The fingerprint page shows the full measured match list. More on the catalog.	1