TCP SYN (p0f)

4:40+24:0:1460:mss*44,8:mss,nop,ws,nop,nop,sok:df,id+,ecn:0

first seen 2026-06-11 00:53 · last seen 2026-06-19 11:20 · 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

4:40+24:0:1460:mss*44,8:mss,nop,ws,nop,nop,sok:df,id+,ecn:0

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleW…

User-Agent claims Windows

TCP SYN initial TTL 40+24 indicates Unix-like

The initial TTL is set by the sending kernel (64 on Unix-like systems, 128 on Windows) and survives NAT. But VPNs, proxies and tunnels legitimately replace the sending stack, so this check never exceeds medium confidence.

Full User-Agent	Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.114 Safari/537.36
Observed TTL	40+24 (observed + path distance → initial)
Claimed OS	Windows
Confidence	medium — repeated co-occurrence, but initial TTL is environmental — capped at medium

medium

2026-06-11

2026-06-19

Decomposed attributes

IP version	`4`
Initial TTL	`40+24`
Options length	`0`
MSS	`1460`
Window size	`mss*44`
Window scale	`8`
Options layout	`mss,nop,ws,nop,nop,sok`
Quirks	`df,id+,ecn`
Payload class	`0`

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)

fingerprint	co-occurrences
`t12d860600_e18388e7f3a3_a1e935682795`	4

HTTP request (JA4H)

fingerprint	co-occurrences
`ge11nn05enus_a1be516b8e6e_000000000000_000000000000`	4

User-Agent

fingerprint	co-occurrences
`Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.114 Safari/537.36`	4

Country

fingerprint	co-occurrences
`SG` · Singapore	4

Network (ASN)

fingerprint	co-occurrences
`AS14061` · DigitalOcean, LLC	4