TCP SYN (p0f)

4:113+15:0:1024:65535,8:mss,nop,ws,nop,nop,sok:df,id+:0

first seen 2026-10-03 16:39 · last seen 2026-10-03 17:10 · JSON

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 version4
Initial TTL113+15
Options length0
MSS1024
Window size65535
Window scale8
Options layoutmss,nop,ws,nop,nop,sok
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
t13d1517h2_8daaf6152771_3cbfd9057e0d Match?Exact match in Thumbprint's published controlled catalog captures: firefox 155.0.1, firefox 154.0, firefox 156.0, +7 more.The fingerprint page shows the full measured match list. More on the catalog.2
t13d1516h2_8daaf6152771_0c27189014cf Match?Exact match in Thumbprint's published controlled catalog captures: firefox 154.0, firefox 155.0.1, firefox 155.0, +4 more.The fingerprint page shows the full measured match list. More on the catalog.1

HTTP request (JA4H)

fingerprintco-occurrences
ge20nr12ru00_1204b4dfdccd_000000000000_0000000000003

HTTP/2 frames (Akamai)

fingerprintco-occurrences
1:65536;2:0;4:131072;5:16384|12517377|3:0:0:22|m,p,a,s Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 155.0.1, +31 more.The fingerprint page shows the full measured match list. More on the catalog.3

TCP SYN (JA4T)

fingerprintco-occurrences
65535_2-1-3-1-1-4_1024_83

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:157.0) Gecko/20100101 Firefox/157.03

Country

fingerprintco-occurrences
US · United States3

Network (ASN)

fingerprintco-occurrences
AS25737 · Jone Broadband LLC3

Cross-transport links

TLS ClientHello fingerprints observed from the same client via the beacon's correlation id on the other transport (e.g. this stack over TCP ↔ that stack over QUIC).

fingerprintlinked observations
q13d0315h3_55b375c5d22e_dc5437974b473