TCP SYN (p0f)

4:55+9:0:1452:mss*44,10:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-09-24 13:11 · last seen 2026-09-24 13:11 · JSON

Decomposed attributes

IP version4
Initial TTL55+9
Options length0
MSS1452
Window sizemss*44
Window scale10
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
t13d1516h2_8daaf6152771_fe7c3632a08d1

HTTP request (JA4H)

fingerprintco-occurrences
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 155.0.1, +31 more.The fingerprint page shows the full measured match list. More on the catalog.1

TCP SYN (JA4T)

fingerprintco-occurrences
64240_2-4-8-1-3_1452_101

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (X11; Linux x86_64; rv:155.0) Gecko/20100101 Firefox/155.01

Country

fingerprintco-occurrences
DE · Germany1

Network (ASN)

fingerprintco-occurrences
AS3320 · Deutsche Telekom AG1

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_78345df32b3a1