TCP SYN (JA4T)

65535_2-1-1-4-1-3_1440_7

first seen 2026-06-30 02:07 · last seen 2026-09-15 19:44 · JSON

Last 7 days (10 observations)

Distinct clients per day (last 30 days, peak 6/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

TCP window	`65535`
Option kinds	`2-1-1-4-1-3`
MSS	`1440`
Window scale	`7`

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)

fingerprint	co-occurrences
`t13d1516h2_8daaf6152771_d8a2da3f94cd` Match?Exact match in Thumbprint's published controlled catalog captures: chromium 149.0.7827.102, chrome 149.0.7827.102, chrome 149.0.7827.156, +25 more.The fingerprint page shows the full measured match list. More on the catalog.	42
`t13d1516h2_8daaf6152771_806a8c22fdea` Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chrome 151.0.7922.137, chromium 151.0.7922.34, +24 more.The fingerprint page shows the full measured match list. More on the catalog.	1
`t13d1517h2_8daaf6152771_cb7bf5808d99` Match?Exact match in Thumbprint's published controlled catalog captures: chrome 152.0.7977.83, chrome 152.0.7977.64, chrome 152.0.7977.65, +5 more.The fingerprint page shows the full measured match list. More on the catalog.	1

HTTP request (JA4H)

fingerprint	co-occurrences
`ge20nn13zhcn_0c2c1d640f3e_000000000000_000000000000`	28
`ge20nn13zhcn_30dc68305204_000000000000_000000000000`	6
`ge20nn13zhcn_9519c2577190_000000000000_000000000000`	4
`ge20nr12zhcn_54b4638ab28b_000000000000_000000000000`	4
`ge20nn13vivn_9519c2577190_000000000000_000000000000`	2

HTTP/2 frames (Akamai)

fingerprint	co-occurrences
`1:65536;2:0;4:6291456;6:262144\|15663105\|1:1:0:256\|m,a,s,p` Match?Exact match in Thumbprint's published controlled catalog captures: chromium 131.0.6778.33, chromium 151.0.7922.34, chrome 151.0.7922.137, +43 more.The fingerprint page shows the full measured match list. More on the catalog.	30
`1:65536;2:0;4:6291456;6:262144\|15663105\|3:1:0:256\|m,a,s,p`	10
`1:65536;2:0;4:6291456;6:262144\|15663105\|1:1:0:220\|m,a,s,p` Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chromium 149.0.7827.102, chrome 149.0.7827.102, +59 more.The fingerprint page shows the full measured match list. More on the catalog.	4

TCP SYN (p0f)

fingerprint	co-occurrences
`6:51+13:0:1440:65535,7:mss,nop,nop,sok,nop,ws:flow:0`	10
`6:48+16:0:1440:65535,7:mss,nop,nop,sok,nop,ws:flow:0`	9
`6:46+18:0:1440:65535,7:mss,nop,nop,sok,nop,ws:flow:0`	5
`6:49+15:0:1440:65535,7:mss,nop,nop,sok,nop,ws:flow:0`	5
`6:47+17:0:1440:65535,7:mss,nop,nop,sok,nop,ws:flow:0`	5
`6:50+14:0:1440:65535,7:mss,nop,nop,sok,nop,ws:flow:0`	4
`6:45+19:0:1440:65535,7:mss,nop,nop,sok,nop,ws:flow:0`	3
`6:40+24:0:1440:65535,7:mss,nop,nop,sok,nop,ws:flow:0`	2
`6:44+20:0:1440:65535,7:mss,nop,nop,sok,nop,ws:flow:0`	1

User-Agent

fingerprint	co-occurrences
`Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.0.0 Safari/537.36`	34
`Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/142.0.0.0 Safari/537.36`	8
`Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/152.0.0.0 Safari/537.36`	1
`Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/151.0.0.0 Safari/537.36`	1

Country

fingerprint	co-occurrences
`CN` · China	42
`US` · United States	2

Network (ASN)

fingerprint	co-occurrences
`AS4837` · CHINA UNICOM China169 Backbone	17
`AS4134` · CHINANET BACKBONE	6
`AS9808` · China Mobile Communications Group Co., Ltd.	3
`AS56040` · China Mobile communications corporation	3
`AS4808` · China Unicom Beijing Province Network	2
`AS140061` · Qinghai Telecom	2
`AS56044` · China Mobile communications corporation	2
`AS63835` · CT HuNan Changsha IDC	2
`AS134764` · CHINANET Guangdong province network	2
`AS9009` · M247 Europe SRL	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).

fingerprint	linked observations
`q13d0311h3_55b375c5d22e_653d80c3fe9d`	2