TLS ClientHello (JA4)

t12d180700_4b22cbed5bed_2dae41c691ec

first seen 2026-06-13 00:46 · last seen 2026-10-25 15:56 · JSON

Inconsistencies

User-Agents observed with this fingerprint that contradict what it proves at the wire. all inconsistencies →

fingerprint User-Agent claims wire shows confidence seen first seen last seen

t12d180700_4b22cbed5bed_2dae41c691ec

Mozilla/5.0 (Windows NT 10.0; Win64; rv:143.0) G…

User-Agent claims Firefox 143.0

TLS cipher list matches no measured Firefox capture

The offered TLS cipher suites match no controlled capture of Firefox. Cipher lists are very stable per browser, so a different one is a real inconsistency — though a TLS-inspecting proxy re-originating the handshake is an honest cause, which holds this at medium.

Full User-Agent	Mozilla/5.0 (Windows NT 10.0; Win64; rv:143.0) Gecko/20100101 Firefox/143.0
Claimed version	143.0
Measured versions	146.0.1, 154.0, 140.0.2, 157.0.1, 151.0.2, 155.0, 153.0.3, 142.0.1, 153.0.4, 152.0.6, 150.0.2, 135.0, 156.0.1, 132.0, 152.0.3, 141.0, 153.0, 151.0.3, 156.0, 152.0.4, 151.0, 152.0.1, 151.0.4, 139.0, 153.0.1, 158.0.1, 152.0.5, 157.0, 158.0, 148.0.2, 137.0, 155.0.1, 159.0, 144.0.2, 154.0.1, 134.0
Layer	cipher suites differ
JA4 label	unlabeled

medium

2026-06-19

2026-07-14

Last 7 days (1 observations)

Distinct clients per day (last 30 days, peak 1/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

Protocol	`t (TLS over TCP)`
TLS version	`12`
SNI	`d (domain)`
Cipher count	`18`
Extension count	`7`
ALPN	`00`
Ciphers	`002f, 0035, 003c, 003d, 009c, 009d, c009, c00a, c013, c014, c023, c024, c027, c028, c02b, c02c, c02f, c030`
Extensions	`000a, 000b, 000d, 0017, 0023, ff01`
Signature algorithms	`0804, 0805, 0806, 0401, 0501, 0201, 0403, 0503, 0203, 0202, 0601, 0603`
JA4_r	`t12d180700_002f,0035,003c,003d,009c,009d,c009,c00a,c013,c014,c023,c024,c027,c028,c02b,c02c,c02f,c030_000a,000b,000d,0017,0023,ff01_0804,0805,0806,0401,0501,0201,0403,0503,0203,0202,0601,0603`
JA4_o (sample)	`t12d180700_c9df9b5f81f0_e7395bd2f4a9`
JA4_ro (sample)	`t12d180700_c02c,c02b,c030,c02f,c024,c023,c028,c027,c00a,c009,c014,c013,009d,009c,003d,003c,0035,002f_0000,000a,000b,000d,0023,0017,ff01_0804,0805,0806,0401,0501,0201,0403,0503,0203,0202,0601,0603`

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.

HTTP request (JA4H)

fingerprint	co-occurrences
`ge11nn040000_cf1edba2959c_000000000000_000000000000`	13
`ge11nn050000_2469c960a647_000000000000_000000000000`	10
`ge11nn050000_fd72ab1ac915_000000000000_000000000000`	4
`ge11nn030000_341eb0d8946c_000000000000_000000000000`	1
`ge11nr11enus_85fe49c621a2_000000000000_000000000000`	1
`ge11nn030000_b0d6a43aa599_000000000000_000000000000` Match?Exact match in Thumbprint's published controlled catalog captures: powershell 5.1.26100.33296, powershell 5.1.26100.33158, powershell 5.1.26100.33438, +3 more.The fingerprint page shows the full measured match list. More on the catalog.	1

TCP SYN (p0f)

fingerprint	co-occurrences
`4:115+13:0:1380:65535,8:mss,nop,ws,nop,nop,sok:df,id+:0`	9
`4:110+18:0:1360:65535,8:mss,nop,ws,nop,nop,sok:df,id+:0`	2
`4:51+13:0:1380:65535,13:mss,sok,ts,nop,ws:df,id+:0`	2
`4:108+20:0:1380:65535,8:mss,nop,ws,nop,nop,sok:df,id+:0`	2
`4:50+14:0:1380:65535,13:mss,sok,ts,nop,ws:df,id+:0`	2
`4:118+10:0:1460:65535,8:mss,nop,ws,nop,nop,sok:df,id+,ecn:0`	1
`4:101+27:0:1380:65535,8:mss,nop,ws,nop,nop,sok:df,id+:0`	1
`4:111+17:0:1380:65535,8:mss,nop,ws,nop,nop,sok:df,id+:0`	1
`4:108+20:0:1380:65535,8:mss,nop,ws,nop,nop,sok:df,id+,ecn:0`	1
`4:47+17:0:1380:65535,13:mss,sok,ts,nop,ws:df,id+:0`	1

TCP SYN (JA4T)

fingerprint	co-occurrences
`65535_2-1-3-1-1-4_1380_8`	7
`65535_2-1-3-1-1-4_1460_8`	1
`65535_2-1-3-1-1-4_1452_8`	1
`64860_2-1-3-1-1-4_1380_8`	1

User-Agent

fingerprint	co-occurrences
`Mozilla/5.0`	7
`Mozilla/5.0 (Windows NT 10.0; Win64; rv:143.0) Gecko/20100101 Firefox/143.0`	7
`Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 Chrome/129.0.0.0 Safari/537.36`	7
`Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 Version/17.0 Safari/605.1.15`	4
`Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:125.0) Gecko/20100101 Firefox/125.0`	1
`Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36 OPR/108.0.0.0`	1
`Mozilla/5.0 (Macintosh; Intel Mac OS X 14_4_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.0.0 Safari/537.36`	1
`Mozilla/5.0 (Linux; Android 15; Pixel 9) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Mobile Safari/537.36`	1
`Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0 Safari/537.36`	1

Country

fingerprint	co-occurrences
`JP` · Japan	15
`SG` · Singapore	4
`US` · United States	3
`BD` · Bangladesh	3
`IN` · India	1
`ES` · Spain	1
`TW` · Taiwan	1
`TR` · Turkey	1
`AT` · Austria	1

Network (ASN)

fingerprint	co-occurrences
`AS63949` · Akamai Connected Cloud	12
`AS13335` · Cloudflare, Inc.	5
`AS21859` · Zenlayer Inc	4
`AS9009` · M247 Europe SRL	2
`AS133605` · Bright Technologies Limited	2
`AS16509` · Amazon.com, Inc.	1
`AS46475` · Limestone Networks, Inc.	1
`AS31898` · Oracle Corporation	1
`AS136141` · Mohammad Kamrul Hasan t/a SK Traders	1
`AS47524` · Turksat Uydu Haberlesme Kablo TV ve Isletme A.S.	1

TLS supported groups

fingerprint	co-occurrences
`001d,0017,0018` Match?Exact match in Thumbprint's published controlled catalog captures: rust-reqwest 0.12.28, rust-reqwest 0.11.27, winhttp 10.0.20348.1, +2 more.The fingerprint page shows the full measured match list. More on the catalog.	1