TCP SYN (p0f)

4:240+15:0:1420:mss*42,8:mss,nop,ws,sok,eol+1:df,id+:0

first seen 2026-07-22 06:06 · last seen 2026-07-22 06:06 · JSON

Decomposed attributes

IP version4
Initial TTL240+15
Options length0
MSS1420
Window sizemss*42
Window scale8
Options layoutmss,nop,ws,sok,eol+1
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
t13d0916h2_f91f431d341e_0c27189014cf1

HTTP request (JA4H)

fingerprintco-occurrences
ge20nr12enus_979a40433f82_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
59640_2-1-3-4-0-0_1420_81

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:152.0) Gecko/20100101 Firefox/152.01

Country

fingerprintco-occurrences
FR · France1

Network (ASN)

fingerprintco-occurrences
AS15557 · Societe Francaise Du Radiotelephone - SFR SA1

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