TCP SYN (p0f)

6:239+16:0:1440:62587,8:mss,sok,ts,nop,ws:flow:0

first seen 2026-10-26 20:59 · last seen 2026-10-26 20:59 · JSON

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

IP version6
Initial TTL239+16
Options length0
MSS1440
Window size62587
Window scale8
Options layoutmss,sok,ts,nop,ws
Quirksflow
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
t13d251100_b78ed14e2fd0_f50d94e863eb1

HTTP request (JA4H)

fingerprintco-occurrences
ge11nn05enus_dff23709e538_000000000000_0000000000001

TCP SYN (JA4T)

fingerprintco-occurrences
62587_2-4-8-1-3_1440_81

User-Agent

fingerprintco-occurrences
ApcosysBot/1.0 (+https://apcosys.net)1

Country

fingerprintco-occurrences
DE · Germany1

Network (ASN)

fingerprintco-occurrences
AS16509 · Amazon.com, Inc.1

TLS supported groups

fingerprintco-occurrences
11ec,11eb,11ed,001d,0017,0018,0019 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.27.3, go-net/http 1.26.10.The fingerprint page shows the full measured match list. More on the catalog.1