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confirmed host

121.4.38.18

Cobalt Strikecommand-and-control server · :443

Last confirmed 2026-08-29, first seen 2026-08-27. On AS45090. Its certificate is shared with 99 other confirmed hosts.

listed last confirmed feed checked TLP:CLEAR SURICATA .RULES SEE THE LIVE FEED →

121.4.38.18:443 · Cobalt Strike

Last confirmed (17 days ago)

first seen2026-08-27 15:53 UTC
serviceip-port · tcp · HTTPS blend-in
networkAS45090 · Shenzhen Tencent Computer Systems Com…
confidence100 / 100
tls certificate87f2085c32b6a2cc709b365f55873e207a9caa10bffecf2fd16d3cf9d94d390c
cert validity2015-05-20 → 2025-05-17
cert typeself-signed
cert key2048-bit
cert serial (decimal)146473198

The certificate names above are what the certificate ASSERTS, not proof this host owns them — a self-signed certificate can claim any subject, so treat a familiar name here as an impersonation attempt rather than an identity.

ja4x2166164053c1_2166164053c1_30d204a01551
cs watermark1234567890

Beacon configuration

callback121.4.38.18 · same as this host
beacon typeHTTPS
cs versionCobalt Strike 4.4 (Aug 04, 2021)
getGET /api/data
postPOST /api/output
user-agentMozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36
sleep30s ±0%
watermark1234567890
server key md5733fba11f750eb7449af7c586fd500cd
inject stub222b8f27dbdfba8ddd559eeca27ea648
spawn to x86%windir%\syswow64\rundll32.exe
spawn to x64%windir%\sysnative\rundll32.exe

Observation history

18d agotoday

Observed on 1 of the 18 days since this archive began recording, 2026-08-29 UTC. Presence is per UTC day: a day is marked when the scanner confirmed this address at least once, not once per scan.

Shared TLS certificate · 99 hosts

These hosts served the same certificate. That is the strongest link this corpus can draw between two addresses, though it evidences a shared BUILD rather than a shared operator: a leaked or resold profile puts the same certificate in different hands. Full cohort →

1.15.76.39Cobalt Strike101.126.10.34Cobalt Strike101.201.103.158Cobalt Strike101.33.200.145Cobalt Strike101.42.136.73Cobalt Strike101.42.255.92Cobalt Strike103.119.47.222Cobalt Strike103.212.186.85Cobalt Strike103.6.169.62Cobalt Strike104.168.102.116Cobalt Strike106.53.61.9Cobalt Strike106.54.21.74Cobalt Strike106.55.25.253Cobalt Strike106.55.46.152Cobalt Strike106.55.47.62Cobalt Strike106.75.249.202Cobalt Strike111.228.5.127Cobalt Strike111.228.55.96Cobalt Strike111.231.116.164Cobalt Strike113.250.188.15Cobalt Strike113.45.253.80Cobalt Strike114.132.216.210Cobalt Strike114.132.46.254Cobalt Strike117.72.181.104Cobalt Strike

Showing 24 of 99. Full cohort →

Shared JA4X issuance template · 270 hosts

These hosts issued certificates from the same template — the same distinguished-name fields hashed in the same order. It links tooling, not necessarily an operator. Full cohort →

1.14.104.208Cobalt Strike1.15.76.39Cobalt Strike101.126.10.34Cobalt Strike101.200.193.211Cobalt Strike101.200.29.195Cobalt Strike101.200.85.0Cobalt Strike101.201.103.158Cobalt Strike101.201.109.2Cobalt Strike101.33.200.145Cobalt Strike101.33.225.32Cobalt Strike101.35.238.122Cobalt Strike101.42.136.73Cobalt Strike101.42.255.92Cobalt Strike101.43.103.154Cobalt Strike102.203.116.201Cobalt Strike103.119.47.222Cobalt Strike103.12.148.37Cobalt Strike103.204.174.212Cobalt Strike103.212.186.85Cobalt Strike103.27.111.130Cobalt Strike103.6.169.62Cobalt Strike104.168.102.116Cobalt Strike106.15.10.2Cobalt Strike106.53.61.9Cobalt Strike

Showing 24 of 270. Full cohort →

Shared Cobalt Strike watermark · 6 hosts

A watermark identifies the Cobalt Strike licence a beacon was generated from. Hosts sharing one were built from the same copy of the software — which is not the same as one operator, since cracked and leaked builds circulate widely and share a watermark by definition.

111.229.248.198Cobalt Strike162.14.150.23Cobalt Strike193.239.86.192Cobalt Strike193.239.86.193Cobalt Strike47.82.234.12Cobalt Strike83.229.123.201Cobalt Strike

Pivots & lookups

same cert → 99 other hosts same ja4x → 270 other hosts same asn → 358 other hosts lookups: virustotal · shodan · censys

Listed in error?

This page is generated from automated scanning and is publicly available. If you are responsible for this address and it should not be listed, write to support@publicmosaic.com — see abuse & takedown for what we need and what happens next, or opt-out to exclude a whole range from scanning.

Addresses are frequently compromised third-party hosts rather than infrastructure their owner stood up. A listing records what a scan observed at a point in time; it is not an allegation about whoever pays for the address.