TCP SYN (p0f)

4:38+26:0:1418:mss*44,9:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-07-17 13:55 · last seen 2026-10-31 08:09 · JSON

Last 7 days (4 observations)

Distinct clients per day (last 30 days, peak 3/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	`38+26`
Options length	`0`
MSS	`1418`
Window size	`mss*44`
Window scale	`9`
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
`t13d1712h2_5b57614c22b0_ef7df7f74e48`	34
`t13d1713h2_5b57614c22b0_02c8e53ee398`	15
`t13d1712h2_5b57614c22b0_d5fe2c511efa`	11

HTTP request (JA4H)

fingerprint	co-occurrences
`ge20nn06enus_32386ca2063f_000000000000_000000000000`	60

HTTP/2 frames (Akamai)

fingerprint	co-occurrences
`2:0;1:4096;8:0;3:1024;4:1048576\|25100289\|0\|a,p,m,s`	60

TCP SYN (JA4T)

fingerprint	co-occurrences
`64240_2-4-8-1-3_1418_9`	60

User-Agent

fingerprint	co-occurrences
`Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko); compatible; ChatGPT-User/1.0; +https://openai.com/bot`	60

Country

fingerprint	co-occurrences
`DK` · Denmark	24
`PL` · Poland	18
`CH` · Switzerland	14
`AU` · Australia	2
`JP` · Japan	1
`NZ` · New Zealand	1

Network (ASN)

fingerprint	co-occurrences
`AS8075` · Microsoft Corporation	60

TLS supported groups

fingerprint	co-occurrences
`001d,0017,0018,0019` Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.21.13.The fingerprint page shows the full measured match list. More on the catalog.	15