TCP SYN (p0f)

4:55+9:0:1460:mss*44,7:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-06-16 14:05 · last seen 2026-09-15 20:45 · JSON

Last 7 days (735 observations)

Distinct clients per day (last 30 days, peak 262/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 TTL55+9
Options length0
MSS1460
Window sizemss*44
Window scale7
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
t13d1516h2_8daaf6152771_806a8c22fdea Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chrome 151.0.7922.137, chromium 151.0.7922.34, +24 more.The fingerprint page shows the full measured match list. More on the catalog.708
t13d301000_1d37bd780c83_3550537cd59b445
t13d1516h2_8daaf6152771_d8a2da3f94cd Match?Exact match in Thumbprint's published controlled catalog captures: chromium 149.0.7827.102, chrome 149.0.7827.102, chrome 149.0.7827.156, +25 more.The fingerprint page shows the full measured match list. More on the catalog.424
t12d330600_5172cef6ed69_021165082e1c89
t13d141000_cbb2034c60b8_e7c285222651 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.22.12.The fingerprint page shows the full measured match list. More on the catalog.15
t12d130600_2d7513195f68_021165082e1c12
t13d131000_f57a46bbacb6_e7c285222651 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.23.12.The fingerprint page shows the full measured match list. More on the catalog.10
t13d1715h2_5b57614c22b0_a54fffd0eb619
t13d1114h2_5e2a75874763_89e9e4bb34199
t13d131100_f57a46bbacb6_ab7e3b40a677 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.5, go-net/http 1.26.4.The fingerprint page shows the full measured match list. More on the catalog.9

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn13enus_0c2c1d640f3e_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: chrome 151.0.7922.137, chrome 151.0.7922.170, chrome 151.0.7922.108, +22 more.The fingerprint page shows the full measured match list. More on the catalog.708
ge11nr08enus_002f1ef91713_000000000000_000000000000445
ge20nn11enus_dbdd560af68b_000000000000_000000000000378
ge11nr040000_e1d2031bdfea_000000000000_000000000000109
ge20nn04enus_989c7cc05c9b_000000000000_00000000000093
ge20nr13enus_0c2c1d640f3e_000000000000_00000000000036
ge11nn030000_cd680697de12_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: powershell 7.6.5, powershell 7.6.4, go-net/http 1.27.0, +7 more.The fingerprint page shows the full measured match list. More on the catalog.13
ge11nn050000_57c5e92682a8_000000000000_00000000000011
ge20nn030000_6dac75bd47eb_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: python-httpx 0.28.1.The fingerprint page shows the full measured match list. More on the catalog.10
ge11nn050000_b223a0ebb0b5_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: python-requests 2.34.2, python-requests 2.33.1, python-requests 2.32.3.The fingerprint page shows the full measured match list. More on the catalog.10

HTTP/2 frames (Akamai)

fingerprintco-occurrences
1:65536;2:0;4:6291456;6:262144|15663105|1:1:0:256|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chromium 131.0.6778.33, chromium 151.0.7922.34, chrome 151.0.7922.137, +42 more.The fingerprint page shows the full measured match list. More on the catalog.715
1:65536;2:0;4:6291456;6:262144|15663105|1:1:0:220|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chromium 149.0.7827.102, chrome 149.0.7827.102, +58 more.The fingerprint page shows the full measured match list. More on the catalog.417
1:65536;2:0;4:6291456;6:262144;4:1048576|15663105|1:0:0:256|m,a,s,p93
4:16777216|16711681|0|m,p,a,s10
2:0;3:100;4:2097152;9:1|10420225|0|m,s,a,p Match?Exact match in Thumbprint's published controlled catalog captures: safari 26.5.2, safari 26.5, safari 26.4, +2 more.The fingerprint page shows the full measured match list. More on the catalog.4
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 154.0, +25 more.The fingerprint page shows the full measured match list. More on the catalog.3
1:65536;2:0;4:6291456;6:262144|15663105|5:1:0:220|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chromium 133.0.6943.16, chrome 150.0.7871.128, chromium 148.0.7778.96, +2 more.The fingerprint page shows the full measured match list. More on the catalog.2
1:65536;2:0;4:131072;5:16384|12517377|1:0:0:42|m,p,a,s2
1:65536;2:0;4:6291456;6:262144|15663105|3:1:0:220|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chromium 151.0.7922.34, chromium 147.0.7727.15, chromium 145.0.7632.6, +21 more.The fingerprint page shows the full measured match list. More on the catalog.2
3:100;4:10485760;2:0|1048510465|0|m,s,a,p Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1, curl 8.5.0.The fingerprint page shows the full measured match list. More on the catalog.2

TCP SYN (JA4T)

fingerprintco-occurrences
64240_2-4-8-1-3_1460_71912

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/150.0.0.0 Safari/537.36708
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36447
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/142.0.0.0 Safari/537.36380
Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.6312.86 Safari/537.3699
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/149.0.0.0 Safari/537.3611
Mozilla/5.0 (X11; Linux x86_64; rv:140.0) Gecko/20100101 Firefox/140.08
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.368
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.190 Safari/537.367
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML,like Gecko) Chrome/95.0.4638.69 Safari/537.366
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/147.0.0.0 Safari/537.365

Country

fingerprintco-occurrences
US · United States1087
FR · France451
CA · Canada130
NL · Netherlands129
SE · Sweden56
RO · Romania18
DE · Germany17
GB · United Kingdom15
GR · Greece12
CO · Colombia4

Network (ASN)

fingerprintco-occurrences
AS30058 · FDCservers.net648
AS51167 · Contabo GmbH446
AS396319 · Oxylabs98
AS211680 · NSEC - Sistemas Informaticos, S.A.97
AS9009 · M247 Europe SRL94
AS210906 · UAB Bite Lietuva90
AS198093 · Foreningen for digitala fri- och rattigheter55
AS3257 · GTT Communications Inc.46
AS32613 · Leaseweb Canada Inc.42
AS27284 · Fourplex Telecom LLC40

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).

fingerprintlinked observations
q13d0311h3_55b375c5d22e_653d80c3fe9d3