Public Mosaic C2 indicators
confirmed host

51.255.5.121

Mythiccommand-and-control server · :7443

On AS16276. Its certificate is shared with 1 other host.

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. A shared value says the hosts were set up alike, not that one operator runs them.

SharedValueOther hosts
TLS certificated95d9934bf01a9bf87a472d3da9ea96a122e7467fb2ac586dcc8296a076a81c71 other host · 1 listed
JA4X templateb757977db3a9_b757977db3a9_b06bda150783210 other hosts · 205 listed

Network context

SharedValueOther hosts
NetworkAS16276 · OVH64 other hosts · 62 listed

Hosts near this one, for context only.

Summary

First seen by the scanner2026-10-18
In this archive since2026-10-18
Evidence1 certificate
Look up elsewhereVirusTotal · Shodan · Censys
About this listingWhat a listing means · Is this your address?

Observation history

Listed on 13 of the 63 days since this archive began recording, 2026-08-29 UTC.

  1. listed
  2. :7443

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
  • 2026-10-18 – 2026-10-30 (13 days)

51.255.5.121:7443 · Mythic

Last confirmed (11 days ago)

first seen2026-10-18 06:13 UTC
serviceip-port · tcp
networkAS16276 · OVH
confidence100 / 100
tls certificated95d9934bf01a9bf87a472d3da9ea96a122e7467fb2ac586dcc8296a076a81c7
cert subject orgMythic
cert issuer orgMythic
cert validity2026-10-14 → 2027-10-14
cert typeself-signed
cert key384-bit
cert serial (hex)544a834cb1f816840cc51c2e61423778
cert serial (decimal)112042044685541706690941762737031755640

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

ja4xb757977db3a9_b757977db3a9_b06bda150783

Hosts sharing a value with this one

210 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 Mythic, as this one is.

AddressSharesLast confirmedStatus
TLS certificate · 1 other host · 1 listed

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

217.182.168.142certificate · JA4X templatelisted
JA4X template · 210 other hosts · 205 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, 1 is listed under an earlier value and 170 are past the 40 hosts shown.

20.193.139.57JA4X templatelisted
87.253.104.147JA4X templatelisted
162.254.37.211JA4X templatelisted
13.215.47.248JA4X templatelisted
3.109.17.133JA4X templatelisted
193.29.13.44JA4X templatelisted
175.43.223.218JA4X templatelisted
92.4.168.97JA4X templatelisted
67.205.148.159JA4X templatelisted
64.227.178.198JA4X templatelisted
5.180.42.176JA4X templatelisted
47.239.61.167JA4X templatelisted
45.135.119.121JA4X templatelisted
38.242.21.31JA4X templatelisted
213.35.118.205JA4X templatelisted
206.209.210.6JA4X templatelisted
20.115.227.161JA4X templatelisted
185.213.22.64JA4X templatelisted
167.99.101.176JA4X templatelisted
165.232.52.148JA4X templatelisted
165.227.48.17JA4X templatelisted
138.197.31.70JA4X templatelisted
138.197.192.243JA4X templatelisted
129.21.21.81JA4X templatelisted
120.79.146.35JA4X templatelisted
89.110.111.68JA4X templatelisted
57.128.171.127JA4X templatelisted
45.192.169.57JA4X templatelisted
20.74.145.114JA4X templatelisted
176.65.144.177JA4X templatelisted
150.241.69.22JA4X templatelisted
143.244.135.17JA4X templatelisted
164.90.158.199JA4X templatelisted
198.199.86.166JA4X templatelisted
38.207.177.71JA4X templatelisted
172.233.97.159JA4X templatelisted
20.200.61.22JA4X templatelisted
77.73.129.82JA4X templatelisted
103.153.254.32JA4X templatelisted

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. Queries hold only addresses, ports and file hashes.

Microsoft Defender XDR (KQL)
DeviceNetworkEvents
| where Timestamp > ago(30d)
| where (RemoteIP == "51.255.5.121" and RemotePort in (7443))
Microsoft Sentinel (KQL)
CommonSecurityLog
| where TimeGenerated > ago(30d)
| where (DestinationIP == "51.255.5.121" and DestinationPort in (7443))
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="51.255.5.121" (All_Traffic.dest_port=7443)))
    by All_Traffic.src_ip All_Traffic.dest_ip All_Traffic.dest_port
Elastic (EQL)
network where
  (destination.ip == "51.255.5.121" and destination.port in (7443))

Cite this record

Plain text, for a ticket or a report
Address 51.255.5.121 Family Mythic (command-and-control server) Ports :7443 Status listed (feed checked 2026-10-30 18:37 UTC) First seen 2026-10-18 Last confirmed 2026-10-19 Record https://publicmosaic.com/ip/51.255.5.121 Source Public Mosaic, TLP:CLEAR