TCP SYN (JA4T)

65535_2-4-8-1-3_1390_12

first seen 2026-06-30 01:35 · last seen 2026-10-31 00:18 · JSON

Last 7 days (162 observations)

Distinct clients per day (last 30 days, peak 25/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 window65535
Option kinds2-4-8-1-3
MSS1390
Window scale12

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
t13d1011h2_61a7ad8aa9b6_3fcd1a44f3e3 Match?Exact match in Thumbprint's published controlled catalog captures: rust-reqwest 0.12.28.The fingerprint page shows the full measured match list. More on the catalog.1980
t13d1713h2_5b57614c22b0_02c8e53ee3988
t13d1712h2_5b57614c22b0_d5fe2c511efa7
t13d1712h2_5b57614c22b0_ef7df7f74e483
t13d311100_e8f1e7e78f70_d41ae481755e Match?Exact match in Thumbprint's published controlled catalog captures: rust-hyper 1.11.1, rust-hyper 1.11.0, rust-hyper 1.12.0, +1 more.The fingerprint page shows the full measured match list. More on the catalog.1

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn050000_a36a3d5685e0_000000000000_000000000000999
ge20nr050000_a36a3d5685e0_000000000000_000000000000981
ge20nr040000_ac162d8a7b0c_000000000000_00000000000018
ge11nr060000_b74b45d8a351_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
2:0;4:2097152;5:16384;6:16384|5177345|0|m,s,a,p Match?Exact match in Thumbprint's published controlled catalog captures: rust-reqwest 0.12.28, rust-reqwest 0.13.5, rust-reqwest 0.13.4, +4 more.The fingerprint page shows the full measured match list. More on the catalog.1980
2:0;1:4096;8:0;3:1024;4:1048576|25100289|0|a,p,m,s18

TCP SYN (p0f)

fingerprintco-occurrences
4:45+19:0:1390:65535,12:mss,sok,ts,nop,ws:df,id+:01090
4:44+20:0:1390:65535,12:mss,sok,ts,nop,ws:df,id+:0879
4:43+21:0:1390:65535,12:mss,sok,ts,nop,ws:df,id+:013
4:48+16:0:1390:65535,12:mss,sok,ts,nop,ws:df,id+:010
4:42+22:0:1390:65535,12:mss,sok,ts,nop,ws:df,id+:03
4:49+15:0:1390:65535,12:mss,sok,ts,nop,ws:df,id+:02
4:46+18:0:1390:65535,12:mss,sok,ts,nop,ws:df,id+:02

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36; compatible; OAI-SearchBot/1.4; +https://openai.com/searchbot1236
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36; compatible; OAI-SearchBot/1.4; robots.txt; +https://openai.com/searchbot423
Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; GPTBot/1.4; +https://openai.com/gptbot)340

Country

fingerprintco-occurrences
US · United States1999

Network (ASN)

fingerprintco-occurrences
AS8075 · Microsoft Corporation1999

TLS supported groups

fingerprintco-occurrences
001d,0017,0018 Match?Exact match in Thumbprint's published controlled catalog captures: rust-reqwest 0.12.28, rust-reqwest 0.11.27, powershell 7.6.8, +1 more.The fingerprint page shows the full measured match list. More on the catalog.329