TCP SYN (JA4T)

65520_2-4-8-1-3_1260_10

first seen 2026-07-28 01:33 · last seen 2026-07-28 01:43 · JSON

Decomposed attributes

TCP window65520
Option kinds2-4-8-1-3
MSS1260
Window scale10

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 154.0, firefox 154.0.1, firefox 155.0.1, +1 more.The fingerprint page shows the full measured match list. More on the catalog.4
t13d1516h2_8daaf6152771_0c27189014cf Match?Exact match in Thumbprint's published controlled catalog captures: firefox 154.0, firefox 155.0.1, firefox 154.0.1.The fingerprint page shows the full measured match list. More on the catalog.1

HTTP request (JA4H)

fingerprintco-occurrences
ge20nr12enus_a72b71f519fc_000000000000_0000000000003
ge20nr11enus_187a9385d229_000000000000_0000000000001
ge20nr13enus_52a9a314672a_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
1:65536;2:0;4:131072;5:16384|12517377|3:0:0:42|m,p,a,s Match?Exact match in Thumbprint's published controlled catalog captures: firefox 154.0, firefox 152.0.5, firefox 152.0.1, +3 more.The fingerprint page shows the full measured match list. More on the catalog.1
1:65536;2:0;4:131072;5:16384|12517377|9:0:0:42|m,p,a,s1
1:65536;2:0;4:131072;5:16384|12517377|13:0:0:42|m,p,a,s1
1:65536;2:0;4:131072;5:16384|12517377|5:0:0:42|m,p,a,s1

TCP SYN (p0f)

fingerprintco-occurrences
6:45+19:0:1260:mss*52,10:mss,sok,ts,nop,ws:flow:05

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (X11; Linux x86_64; rv:150.0) Gecko/20100101 Firefox/150.05

Country

fingerprintco-occurrences
GB · United Kingdom5

Network (ASN)

fingerprintco-occurrences
AS9009 · M247 Europe SRL5

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