TCP SYN (p0f)

6:41+23:0:1440:mss*45,10:mss,sok,ts,nop,ws:flow:0

first seen 2026-06-30 05:44 · last seen 2026-10-30 10:47 · JSON

Last 7 days (9 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 version6
Initial TTL41+23
Options length0
MSS1440
Window sizemss*45
Window scale10
Options layoutmss,sok,ts,nop,ws
Quirksflow
Payload class0

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)

fingerprintco-occurrences
t13d3113h1_1d947a95fc68_7e1102d2036b9
t13d1312h2_f57a46bbacb6_ab7e3b40a677 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.10, go-net/http 1.26.9, +7 more.The fingerprint page shows the full measured match list. More on the catalog.7
t13d3112h1_1d947a95fc68_fa269c3d986d4
t13d1011h1_61a7ad8aa9b6_3a8073edd8ef2
t13d1713h1_ab0a1bf427ad_ecd0401ec68b Match?Exact match in Thumbprint's published controlled catalog captures: python-httpx 0.28.1.The fingerprint page shows the full measured match list. More on the catalog.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
t13d3013h2_1d37bd780c83_8537cf56674e Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.18.0.The fingerprint page shows the full measured match list. More on the catalog.1
t13d131100_f57a46bbacb6_f50d94e863eb Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.27.1, go-net/http 1.27.3, go-net/http 1.27.0, +1 more.The fingerprint page shows the full measured match list. More on the catalog.1

HTTP request (JA4H)

fingerprintco-occurrences
ge11nn07cscz_d4021d63333c_000000000000_00000000000011
ge20nn04enus_39a3ba4480e8_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: urlsession 6.1.2.The fingerprint page shows the full measured match list. More on the catalog.4
ge11nn06cscz_f604b96915d0_000000000000_0000000000002
ge20nn030000_80b089f68b8e_000000000000_0000000000001
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.1
ge20nn04enus_118e0135d6ef_000000000000_0000000000001
he20nn030000_80b089f68b8e_000000000000_0000000000001
ge11nn07*000_131b6413da1e_000000000000_0000000000001
ge20nn030000_bf75ddd0bb29_000000000000_0000000000001
ge20nn04enus_ded3c6d8f0eb_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
2:0;4:4194304;5:16384;6:10485760|1073741824|0|a,m,p,s Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.10, go-net/http 1.26.9, +8 more.The fingerprint page shows the full measured match list. More on the catalog.7
1:4096;2:0;4:65535;5:16384;3:100;6:65536|16777216|0|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: python-httpx 0.28.1.The fingerprint page shows the full measured match list. More on the catalog.2
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)

fingerprintco-occurrences
64800_2-4-8-1-3_1440_1027

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (compatible; SeznamBot/4.0; +https://o-seznam.cz/napoveda/vyhledavani/en/seznambot-crawler/)13
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.362
DataFoundationResearch/0.1 (+contact@example.com)2
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.361
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.361
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.361
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.361
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/604.11
curl/8.14.11
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.10 Safari/605.1.11

Country

fingerprintco-occurrences
CZ · Czechia13
DE · Germany11
SG · Singapore1
IN · India1
SI · Slovenia1

Network (ASN)

fingerprintco-occurrences
AS43037 · Seznam.cz, a.s.13
AS24940 · Hetzner Online GmbH11
AS16276 · OVH SAS1
AS55836 · Reliance Jio Infocomm Limited1
AS2107 · ARNES1

TLS supported groups

fingerprintco-occurrences
001d,0017,0018,0019,001e,0100,0101,0102,0103,0104 Match?Exact match in Thumbprint's published controlled catalog captures: java-httpclient 17.0.19, java-httpclient 11.0.31, java-urlconnection 17.0.19, +2 more.The fingerprint page shows the full measured match list. More on the catalog.9
11ec,001d,0017,001e,0018,0019,0100,0101 Match?Exact match in Thumbprint's published controlled catalog captures: python-httpx 0.28.1, python-requests 2.34.2, curl 8.23.0, +4 more.The fingerprint page shows the full measured match list. More on the catalog.1