TCP SYN (p0f)

4:49+15:0:1330:mss*49,10:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-08-19 01:03 · last seen 2026-09-13 22:20 · JSON

Last 7 days (4 observations)

Distinct clients per day (last 30 days, peak 4/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 TTL49+15
Options length0
MSS1330
Window sizemss*49
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
t13d1515h1_8daaf6152771_de4a06bb82e35
t13d1717h2_5b57614c22b0_3cbfd9057e0d Match?Exact match in Thumbprint's published controlled catalog captures: firefox 148.0.2, firefox 144.0.2, firefox 142.0.1, +6 more.The fingerprint page shows the full measured match list. More on the catalog.2
t13d1516h1_8daaf6152771_1a63afa7c4782
t13d1515h1_8daaf6152771_0a20fe35d3a51

HTTP request (JA4H)

fingerprintco-occurrences
ge11nn13enus_9db22d02e17a_000000000000_0000000000008
ge20nr10enus_b3034183f430_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 154.0, +21 more.The fingerprint page shows the full measured match list. More on the catalog.2

HTTP/2 frames (Akamai)

fingerprintco-occurrences
1:65536;2:0;4:131072;5:16384|12517377|5:0:0:22|m,p,a,s Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0.3, firefox 154.0, firefox 153.0, +8 more.The fingerprint page shows the full measured match list. More on the catalog.1
1:65536;2:0;4:131072;5:16384|12517377|3:0:0:22|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
65170_2-4-8-1-3_1330_1010

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.67 Safari/537.363
Mozilla/5.0 (X11; Linux x86_64; rv:140.0) Gecko/20100101 Firefox/140.02
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.362
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.361
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.361
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/110.0.0.0 Safari/537.361

Country

fingerprintco-occurrences
US · United States7
ES · Spain2
FR · France1

Network (ASN)

fingerprintco-occurrences
AS209854 · Cyberzone S.A.4
AS212238 · Datacamp Limited3
AS203020 · HostRoyale Technologies Pvt Ltd2
AS60068 · Datacamp Limited1

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
q13d0314h3_55b375c5d22e_61e396c58b1f2