TCP SYN (p0f)

4:83+?:0:1380:65535,8:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-07-28 10:26 · last seen 2026-09-15 07:03 · JSON

Last 7 days (2 observations)

Distinct clients per day (last 30 days, peak 3/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 version4
Initial TTL83+?
Options length0
MSS1380
Window size65535
Window scale8
Options layoutmss,sok,ts,nop,ws
Quirksdf,id+
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_5ac7197df9d217

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn030000_80b089f68b8e_000000000000_0000000000007
ge20nn020000_e5a56608905c_000000000000_0000000000005
ge20nn070000_1903711a2262_000000000000_0000000000003
ge20nn09enus_c5abe4666a67_000000000000_0000000000002

HTTP/2 frames (Akamai)

fingerprintco-occurrences
1:4096;2:0;5:16384;6:131072;3:100;4:65536|26148865|0|m,s,p,a15
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,a2

TCP SYN (JA4T)

fingerprintco-occurrences
65535_2-4-8-1-3_1380_817

User-Agent

fingerprintco-occurrences
facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)7
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36 (compatible; meta-externalagent/1.1 (+https://developers.facebook.com/docs/sharing/webmasters/crawler))5
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-externalagent/1.1 (+https://developers.facebook.com/docs/sharing/webmasters/crawler))4
Mozilla/5.0 (X11; Linux x86_64; rv:147.0) Gecko/20100101 Firefox/147.0 (compatible; meta-externalagent/1.1 (+https://developers.facebook.com/docs/sharing/webmasters/crawler))1

Country

fingerprintco-occurrences
US · United States13
SG · Singapore4

Network (ASN)

fingerprintco-occurrences
AS32934 · Facebook, Inc.17