TCP SYN (p0f)

6:48+16:0:1380:65535,8:mss,sok,ts,nop,ws::0

first seen 2026-06-25 13:02 · last seen 2026-09-14 12:51 · JSON

Last 7 days (18 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

IP version6
Initial TTL48+16
Options length0
MSS1380
Window size65535
Window scale8
Options layoutmss,sok,ts,nop,ws
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
t13d3111h2_e8f1e7e78f70_5ac7197df9d285
t13d2212h1_3522af84f765_8d633dac71241

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn040000_3dccbaa13f05_000000000000_00000000000036
ge20nn030000_80b089f68b8e_000000000000_00000000000021
ge20nn030000_0d4c7aba53a3_000000000000_00000000000010
ge20nn020000_5594a17e7e7e_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1, curl 8.5.0, curl 8.18.0, +9 more.The fingerprint page shows the full measured match list. More on the catalog.8
ge20nn09enus_c5abe4666a67_000000000000_0000000000003
ge20nn11enus_08fd186dd996_000000000000_0000000000003
ge20nn040000_8ab5aeda5c38_000000000000_0000000000002
ge20nn020000_e5a56608905c_000000000000_0000000000002
ge11nn050000_9caab87a0805_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
1:4096;2:0;5:16384;6:131072;3:100;4:65536|26148865|0|m,s,p,a71
1:4096;2:0;5:16384;6:131072;3:100;4:65536;11105:65535;11106:65535;11107:65535;11108:10;11109:10|26148865|0|m,s,p,a14

TCP SYN (JA4T)

fingerprintco-occurrences
65535_2-4-8-1-3_1380_884

User-Agent

fingerprintco-occurrences
facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)80
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36 (compatible; meta-webindexer/1.1 (+https://developers.facebook.com/docs/sharing/webmasters/crawler))2
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36 (compatible; meta-webindexer/1.1 (+https://developers.facebook.com/docs/sharing/webmasters/crawler))2
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36 Edg/145.0.0.0 (compatible; meta-webindexer/1.1 (+https://developers.facebook.com/docs/sharing/webmasters/crawler))1
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:147.0) Gecko/20100101 Firefox/147.0 (compatible; meta-webindexer/1.1 (+https://developers.facebook.com/docs/sharing/webmasters/crawler))1

Country

fingerprintco-occurrences
US · United States69
DE · Germany13
GB · United Kingdom4

Network (ASN)

fingerprintco-occurrences
AS32934 · Facebook, Inc.86