TLS ClientHello (JA4)

t13d1717h2_4086585eccf2_3cbfd9057e0d

first seen 2026-09-29 14:39 · last seen 2026-09-29 14:39 · 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

t13d1717h2_4086585eccf2_3cbfd9057e0d

Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv…

User-Agent claims Firefox 156.0

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 (Macintosh; Intel Mac OS X 10.15; rv:156.0) Gecko/20100101 Firefox/156.0
Claimed version	156.0
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

2026-09-29

Decomposed attributes

Protocol	`t (TLS over TCP)`
TLS version	`13`
SNI	`d (domain)`
Cipher count	`17`
Extension count	`17`
ALPN	`h2`
Ciphers	`002f, 0033, 0035, 0039, 009c, 009d, 1301, 1302, 1303, c013, c014, c02b, c02c, c02f, c030, cca8, cca9`
Extensions	`0005, 000a, 000b, 000d, 0012, 0017, 001b, 001c, 0022, 0023, 002b, 002d, 0033, fe0d, ff01`
Signature algorithms	`0403, 0503, 0603, 0804, 0805, 0806, 0401, 0501, 0601, 0203, 0201`
JA4_r	`t13d1717h2_002f,0033,0035,0039,009c,009d,1301,1302,1303,c013,c014,c02b,c02c,c02f,c030,cca8,cca9_0005,000a,000b,000d,0012,0017,001b,001c,0022,0023,002b,002d,0033,fe0d,ff01_0403,0503,0603,0804,0805,0806,0401,0501,0601,0203,0201`
JA4_o (sample)	`t13d1717h2_02398f731a05_df135d36b6d5`
JA4_ro (sample)	`t13d1717h2_1301,1303,1302,c02b,c02f,cca9,cca8,c02c,c030,c013,c014,0033,0039,009c,009d,002f,0035_0000,0017,ff01,000a,000b,0023,0010,0005,0022,0012,0033,002b,000d,002d,001c,001b,fe0d_0403,0503,0603,0804,0805,0806,0401,0501,0601,0203,0201`

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
`ge20nn11enus_3901d4197baf_000000000000_000000000000` Match?Exact match in Thumbprint's published controlled catalog captures: firefox 154.0, firefox 152.0.5, firefox 153.0.1, +3 more.The fingerprint page shows the full measured match list. More on the catalog.	1

HTTP/2 frames (Akamai)

fingerprint	co-occurrences
`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

TCP SYN (p0f)

fingerprint	co-occurrences
`4:51+13:0:1460:mss*29,12:mss,sok,ts,nop,ws:df,id+:0`	1

TCP SYN (JA4T)

fingerprint	co-occurrences
`42340_2-4-8-1-3_1460_12`	1

User-Agent

fingerprint	co-occurrences
`Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:156.0) Gecko/20100101 Firefox/156.0`	1

Country

fingerprint	co-occurrences
`US` · United States	1

Network (ASN)

fingerprint	co-occurrences
`AS138997` · Eons Data Communications Limited	1