TCP SYN (p0f)

6:50+14:0:1440:65535,8:mss,nop,ws,nop,nop,sok:flow:0

first seen 2026-07-01 15:37 · last seen 2026-08-27 18:34 · 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 version6
Initial TTL50+14
Options length0
MSS1440
Window size65535
Window scale8
Options layoutmss,nop,ws,nop,nop,sok
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
t13d201200_2b729b4bf6f3_e24568c0d4402
t13d1616h2_86a278354501_0c27189014cf Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 152.0.6, +10 more.The fingerprint page shows the full measured match list. More on the catalog.1

HTTP request (JA4H)

fingerprintco-occurrences
po11nn07nlnl_7d361e250c48_000000000000_0000000000002
ge20nr12enus_1204b4dfdccd_000000000000_0000000000001

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 154.0, +25 more.The fingerprint page shows the full measured match list. More on the catalog.1

TCP SYN (JA4T)

fingerprintco-occurrences
65535_2-1-3-1-1-4_1440_83

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:151.0) Gecko/20100101 Firefox/151.01
Mozilla/5.0 (Windows NT 6.2; arm64) AppleWebKit/537.36 (KHTML, like Gecko) Safari/11.0.0.0 Safari/537.361
Mozilla/5.0 (Linux; Android 10; x64) AppleWebKit/537.36 (KHTML, like Gecko) Firefox/71.0.0.0 Safari/537.361

Country

fingerprintco-occurrences
NL · Netherlands2
US · United States1

Network (ASN)

fingerprintco-occurrences
AS1136 · KPN B.V.2
AS22773 · Cox Communications Inc.1

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_dc5437974b471