Public Mosaic C2 indicators
confirmed host

8.166.128.186

Cobalt Strikecommand-and-control server · :50053

On AS37963. Its certificate is shared with 145 other hosts.

listed last confirmed feed checked TLP:CLEAR Suricata rules Show in the live feed

Relations

Values this address shares with other hosts in this archive, rarest first, watermarks last. A shared value says the hosts were set up alike, not that one operator runs them.

SharedValueOther hosts
TLS certificate87f2085c32b6a2cc709b365f55873e207a9caa10bffecf2fd16d3cf9d94d390c145 other hosts · 143 listed
JA4X template2166164053c1_2166164053c1_30d204a01551420 other hosts · 417 listed
Cobalt Strike watermark39114493842 other hosts · 42 listed

A Cobalt Strike watermark is a weak link: cracked and leaked builds share one.

Not shared with any other host in this archive: 1 server key.

Network context

SharedValueOther hosts
NetworkAS37963 · Hangzhou Alibaba Advertising431 other hosts · 430 listed

Hosts near this one, for context only.

Summary

First seen by the scanner2026-09-28
In this archive since2026-09-28
Evidence1 certificate · 1 beacon configuration · 1 file served
Look up elsewhereVirusTotal · Shodan · Censys
About this listingWhat a listing means · Is this your address?

Observation history

Listed on 33 of the 63 days since this archive began recording, 2026-08-29 UTC.

  1. listed
  2. :50053

2026-08-292026-10-30

  • first seen to last confirmed
  • listed after its last confirmation

A marked day is a UTC day the feed listed this address. The feed keeps a listener for up to 90 days after its last confirmation, so a listed day is not a confirmation. A listener no longer in the feed is drawn to its last confirmation.

Listed days as dates
  • 2026-09-28 – 2026-10-30 (33 days)

8.166.128.186:50053 · Cobalt Strike

Last confirmed (30 days ago)

first seen2026-09-28 03:06 UTC
serviceip-port · tcp
networkAS37963 · Hangzhou Alibaba Advertising
confidence100 / 100
tls certificate87f2085c32b6a2cc709b365f55873e207a9caa10bffecf2fd16d3cf9d94d390c
cert validity2015-05-20 → 2025-05-17
cert typeself-signed
cert key2048-bit
cert serial (hex)08bb00ee
cert serial (decimal)146473198

The names above are what the certificate claims, not proof that this host owns them. Treat a familiar name as a likely impersonation.

ja4x2166164053c1_2166164053c1_30d204a01551
cs watermark391144938

Beacon configuration

callback8.166.128.186 · same as this host
beacon typeHTTPS
cs versionCobalt Strike 4.7 (Aug 17, 2022)
getGET /match
postPOST /submit.php
user-agentMozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0)
sleep60s ±0%
watermark391144938
server key md536dc2cb577872ac358d75dd39210a6fb
inject stubb50b86d735412685eb6044ad8d01781c
spawn to x86%windir%\syswow64\rundll32.exe
spawn to x64%windir%\sysnative\rundll32.exe

Hosts sharing a value with this one

431 other hosts in this archive share at least one value with this one. Each is listed once, under its first shared value in Relations order. Dates and status are from the records that share a value. Showing the 40 that rank first. Every host shown is labelled Cobalt Strike, as this one is.

AddressSharesLast confirmedStatus
TLS certificate · 145 other hosts · 143 listed

These hosts presented the same certificate. Leaked or resold profiles reuse certificates, so this is not evidence of a single operator.

Of these, 105 are past the 40 hosts shown.

8.163.59.20certificate · JA4X templatelisted
117.72.182.5certificate · JA4X templatelisted
192.252.185.78certificate · JA4X templatelisted
49.232.42.116certificate · JA4X templatelisted
113.250.188.15certificate · JA4X templatelisted
47.105.36.109certificate · JA4X template · watermarklisted
101.42.255.92certificate · JA4X templatelisted
111.231.116.164certificate · JA4X templatelisted
117.72.181.104certificate · JA4X templatelisted
60.247.206.23certificate · JA4X template · watermarklisted
222.255.215.42certificate · JA4X templatelisted
82.156.219.31certificate · JA4X templatelisted
8.222.166.74certificate · JA4X templatelisted
64.177.112.233certificate · JA4X templatelisted
192.3.251.109certificate · JA4X templatelisted
176.123.5.4certificate · JA4X templatelisted
173.208.167.73certificate · JA4X templatelisted
120.79.64.164certificate · JA4X templatelisted
110.42.225.241certificate · JA4X templatelisted
82.156.186.185certificate · JA4X templatelisted
47.86.184.71certificate · JA4X templatelisted
38.76.183.197certificate · JA4X templatelisted
23.238.82.42certificate · JA4X templatelisted
123.207.214.140certificate · JA4X templatelisted
117.158.148.164certificate · JA4X templatelisted
111.228.5.127certificate · JA4X templatelisted
85.11.182.104certificate · JA4X templatelisted
39.100.64.125certificate · JA4X template · watermarklisted
203.98.68.25certificate · JA4X templatelisted
203.98.68.24certificate · JA4X templatelisted
140.143.193.143certificate · JA4X templatelisted
1.117.74.144certificate · JA4X templatelisted
124.220.22.82certificate · JA4X templatelisted
121.4.38.18certificate · JA4X templatelisted
192.144.171.134certificate · JA4X templatelisted
47.84.50.235certificate · JA4X templatelisted
14.225.212.124certificate · JA4X templatelisted
212.14.244.222certificate · JA4X templatelisted
106.53.61.9certificate · JA4X templatelisted
129.28.122.92certificate · JA4X templatelisted
JA4X template · 420 other hosts · 417 listed

These hosts’ certificates share one JA4X template, which points to the same certificate tooling. It is not evidence of a single operator.

Of these, 40 are listed under an earlier value and 380 are past the 40 hosts shown.

Cobalt Strike watermark · 42 other hosts · 42 listed

The watermark identifies the Cobalt Strike licence a beacon was built with. Cracked and leaked builds share watermarks widely, so it is not evidence of a single operator.

Of these, 3 are listed under an earlier value and 39 are past the 40 hosts shown.

Samples served · 1 file

Files this address was seen serving, each identified by running or analysing it. A widely distributed file can reach unrelated hosts.

Every file here was served on :50053.

FileConfirmedFile last seen
1b01022f7f18829f6275aff63233f40f86ab2246014b632845990958c36f13e6analysed

Deploy

Suricata rules and hunt queries for this address’s 1 listed listener.

Suricata rules

Each query searches the last 30 days of your logs for connections to these listeners and for the 1 file this address served. Queries hold only addresses, ports and file hashes.

Microsoft Defender XDR (KQL)
DeviceNetworkEvents
| where Timestamp > ago(30d)
| where (RemoteIP == "8.166.128.186" and RemotePort in (50053))
DeviceFileEvents
| where Timestamp > ago(30d)
| where SHA256 in ("1b01022f7f18829f6275aff63233f40f86ab2246014b632845990958c36f13e6")
Microsoft Sentinel (KQL)
CommonSecurityLog
| where TimeGenerated > ago(30d)
| where (DestinationIP == "8.166.128.186" and DestinationPort in (50053))
Splunk (SPL, CIM data models)
| tstats summariesonly=false count min(_time) as first_time max(_time) as last_time
    from datamodel=Network_Traffic where earliest=-30d
    ((All_Traffic.dest_ip="8.166.128.186" (All_Traffic.dest_port=50053)))
    by All_Traffic.src_ip All_Traffic.dest_ip All_Traffic.dest_port
| tstats summariesonly=false count min(_time) as first_time max(_time) as last_time
    from datamodel=Endpoint.Filesystem where earliest=-30d
    (Filesystem.file_hash="1b01022f7f18829f6275aff63233f40f86ab2246014b632845990958c36f13e6")
    by Filesystem.dest Filesystem.file_path Filesystem.file_hash
Elastic (EQL)
network where
  (destination.ip == "8.166.128.186" and destination.port in (50053))
file where file.hash.sha256 in ("1b01022f7f18829f6275aff63233f40f86ab2246014b632845990958c36f13e6")

Cite this record

Plain text, for a ticket or a report
Address 8.166.128.186 Family Cobalt Strike (command-and-control server) Ports :50053 Status listed (feed checked 2026-10-30 18:37 UTC) First seen 2026-09-28 Last confirmed 2026-09-30 Record https://publicmosaic.com/ip/8.166.128.186 Source Public Mosaic, TLP:CLEAR