TCP SYN (p0f)

4:51+13:0:1460:mss*44,9:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-07-01 14:40 · last seen 2026-10-27 09:22 · JSON

Last 7 days (1 observations)

Distinct clients per day (last 30 days, peak 6/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 version4
Initial TTL51+13
Options length0
MSS1460
Window sizemss*44
Window scale9
Options layoutmss,sok,ts,nop,ws
Quirksdf,id+
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
t13d3013h2_1d37bd780c83_8537cf56674e9
t13d251100_b78ed14e2fd0_ab7e3b40a6775
t13d141100_cbb2034c60b8_e5728521abd42
t13d1910h1_9dc949149365_97f8aa674fd92

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn030000_bf75ddd0bb29_000000000000_0000000000008
ge11nn050000_57c5e92682a8_000000000000_0000000000005
ge11nn040000_e1d2031bdfea_000000000000_0000000000002
ge11nn030000_fe444ad14866_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.16.0, curl 7.88.1, curl 8.21.0, +1 more.The fingerprint page shows the full measured match list. More on the catalog.2
ge20nn040000_fc47e34348bb_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-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.9

TCP SYN (JA4T)

fingerprintco-occurrences
64240_2-4-8-1-3_1460_918

User-Agent

fingerprintco-occurrences
curl/8.14.18
Mozilla/5.0 (compatible; UnifiedPaths/1.0)2
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:149.0) Gecko/20100101 Firefox/149.01
FreshRSS/1.29.1 (Linux; https://freshrss.org)1
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:156.0) Gecko/20100101 Firefox/156.01
Mozilla/5.0 (Windows NT 6.1; rv:38.0) Gecko/20100101 Firefox/38.01
Mozilla/5.0 (Kubuntu; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.361
Mozilla/5.0 (X11; Linux x86_64; rv:1.9.5.20) Gecko/ Firefox/3.6.141
Mozilla/5.0 (CentOS; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.361
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:100.0) Gecko/20100101 Firefox/100.01

Country

fingerprintco-occurrences
DE · Germany8
US · United States5
NL · Netherlands2
CA · Canada1
IN · India1
IT · Italy1

Network (ASN)

fingerprintco-occurrences
AS399979 · 49.3 Networking LLC7
AS63949 · Akamai Connected Cloud6
AS14061 · DigitalOcean, LLC2
AS12989 · Black HOST Ltd2
AS3209 · Vodafone GmbH1

TLS supported groups

fingerprintco-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.8
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.1