TCP SYN (p0f)
4:47+17:0:1380:mss*44,10:mss,sok,ts,nop,ws:df,id+:0
first seen 2026-08-31 05:54 · last seen 2026-10-12 08:53 · JSON
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 version | 4 |
|---|---|
| Initial TTL | 47+17 |
| Options length | 0 |
| MSS | 1380 |
| Window size | mss*44 |
| Window scale | 10 |
| Options layout | mss,sok,ts,nop,ws |
| Quirks | df,id+ |
| 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 |
|---|---|
t13d1715h2_5b57614c22b0_a54fffd0eb61 | 6 |
t13d1517h2_8daaf6152771_3cbfd9057e0d Match?Exact match in Thumbprint's published controlled catalog captures: firefox 155.0.1, firefox 154.0, firefox 156.0, +8 more.The fingerprint page shows the full measured match list. More on the catalog. | 3 |
t13d1312h2_f57a46bbacb6_ab7e3b40a677 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.10, go-net/http 1.26.9, +7 more.The fingerprint page shows the full measured match list. More on the catalog. | 2 |
t13d1714h2_5b57614c22b0_53a6d0ab1c42 | 2 |
HTTP request (JA4H)
HTTP/2 frames (Akamai)
| fingerprint | co-occurrences |
|---|---|
1:65536;2:0;4:131072;5:16384|12517377|3:0:0:22|m,p,a,s Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 155.0.1, +32 more.The fingerprint page shows the full measured match list. More on the catalog. | 5 |
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. | 2 |
2:0;4:4194304;5:16384;6:10485760|1073741824|0|a,m,p,s Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.10, go-net/http 1.26.9, +8 more.The fingerprint page shows the full measured match list. More on the catalog. | 2 |
1:65536;2:0;4:131072;5:16384|12517377|5:0:0:22|m,p,a,s Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0.3, firefox 154.0, firefox 153.0, +13 more.The fingerprint page shows the full measured match list. More on the catalog. | 1 |
1:65536;2:0;4:131072;5:16384|12517377|7:0:0:22|m,p,a,s Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0.3, firefox 158.0.1, firefox 155.0, +4 more.The fingerprint page shows the full measured match list. More on the catalog. | 1 |
1:65536;2:0;4:131072;5:16384|12517377|7:0:0:42|m,p,a,s | 1 |
1:65536;2:0;4:131072;5:16384|12517377|5:0:0:42|m,p,a,s | 1 |
TCP SYN (JA4T)
| fingerprint | co-occurrences |
|---|---|
64240_2-4-8-1-3_1380_10 | 13 |
User-Agent
Country
| fingerprint | co-occurrences |
|---|---|
DK · Denmark | 11 |
SE · Sweden | 2 |
Network (ASN)
| fingerprint | co-occurrences |
|---|---|
AS3292 · TDC Holding A/S | 11 |
AS9009 · M247 Europe SRL | 2 |
Cross-transport links
TLS ClientHello fingerprints observed from the same client via the beacon's correlation id on the other transport (e.g. this stack over TCP ↔ that stack over QUIC).
| fingerprint | linked observations |
|---|---|
q13d0315h3_55b375c5d22e_dc5437974b47 | 3 |