ThreatFox: Mirai IOCs | SOC Hunt Feed

Hunt Hypothesis

This hunt detects active network reconnaissance and potential botnet recruitment by identifying traffic matching known Mirai malware indicators of compromise (IOCs). Proactively hunting for these signatures in Azure Sentinel is critical to rapidly isolate infected IoT devices before they can launch large-scale distributed denial-of-service attacks or pivot laterally within the enterprise network.

IOC Summary

Malware Family: Mirai Total IOCs: 13 IOC Types: domain, ip:port

Type	Value	Threat Type	First Seen	Confidence
ip:port	`2[.]26[.]81[.]46:1999`	botnet_cc	2026-08-14	80%
domain	`afterhours.click`	botnet_cc	2026-08-14	100%
domain	`imagiraffe.shop`	botnet_cc	2026-08-14	100%
ip:port	`135[.]136[.]191[.]231:8080`	botnet_cc	2026-08-14	100%
domain	`nightslikethis.club`	botnet_cc	2026-08-14	100%
domain	`chickenfriedwatermelonkoolaid.store`	botnet_cc	2026-08-14	100%
ip:port	`135[.]136[.]191[.]231:23`	botnet_cc	2026-08-14	100%
ip:port	`135[.]136[.]191[.]231:123`	botnet_cc	2026-08-14	100%
ip:port	`135[.]136[.]191[.]231:80`	botnet_cc	2026-08-14	100%
ip:port	`135[.]136[.]191[.]231:25565`	botnet_cc	2026-08-14	100%
ip:port	`3[.]34[.]139[.]65:123`	botnet_cc	2026-08-14	100%
ip:port	`45[.]38[.]249[.]63:1004`	payload_delivery	2026-08-14	50%
ip:port	`172[.]104[.]49[.]49:3667`	botnet_cc	2026-08-14	100%

KQL: Ip Hunt

// Hunt for network connections to known malicious IPs
// Source: ThreatFox - Mirai
let malicious_ips = dynamic(["2.26.81.46", "135.136.191.231", "45.38.249.63", "172.104.49.49", "3.34.139.65"]);
CommonSecurityLog
| where DestinationIP in (malicious_ips) or SourceIP in (malicious_ips)
| project TimeGenerated, SourceIP, DestinationIP, DestinationPort, DeviceAction, Activity
| order by TimeGenerated desc

KQL: Ip Hunt Device

// Hunt in Defender for Endpoint network events
let malicious_ips = dynamic(["2.26.81.46", "135.136.191.231", "45.38.249.63", "172.104.49.49", "3.34.139.65"]);
DeviceNetworkEvents
| where RemoteIP in (malicious_ips)
| project Timestamp, DeviceName, RemoteIP, RemotePort, InitiatingProcessFileName, ActionType
| order by Timestamp desc

KQL: Domain Hunt

// Hunt for DNS queries to known malicious domains
// Source: ThreatFox - Mirai
let malicious_domains = dynamic(["afterhours.click", "imagiraffe.shop", "nightslikethis.club", "chickenfriedwatermelonkoolaid.store"]);
DnsEvents
| where Name has_any (malicious_domains)
| project TimeGenerated, Computer, Name, IPAddresses, QueryType
| order by TimeGenerated desc

Required Data Sources

Sentinel Table	Notes
`CommonSecurityLog`	Ensure this data connector is enabled
`DeviceNetworkEvents`	Ensure this data connector is enabled
`DnsEvents`	Ensure this data connector is enabled

References

ThreatFox — Mirai

False Positive Guidance

Here are specific false positive scenarios and corresponding filters for the ThreatFox: Mirai IOCs rule in an enterprise environment:

Scenario: IoT Device Firmware Updates via Scheduled Tasks
- Context: Enterprise-managed IoT devices (e.g., smart conference room displays, industrial sensors) often run scheduled firmware update jobs that connect to vendor cloud repositories. These updates may originate from IP addresses or utilize ports that overlap with Mirai’s known IOCs (specifically UDP/1935 and TCP/8080).
- Filter/Exclusion: Create a whitelist exclusion for the specific MAC address ranges of managed IoT subnets or exclude traffic where the Source Device Type is “IoT” and the Destination Port matches the Mirai IOCs during defined maintenance windows (e.g., 02:00–04:00 UTC).
Scenario: Network Scanning by Internal Security Tools
- Context: Internal vulnerability scanners like Tenable Nessus, Qualys, or Microsoft Defender for Cloud periodically probe network segments. These tools often initiate connections to external IP ranges that may coincide with Mirai’s command-and-control (C2) infrastructure, triggering alerts when the scanner mimics IoT device behavior.
- Filter/Exclusion: Exclude traffic where the Source Host belongs to the “Security Operations” OU or matches specific scanner hostnames (e.g., scanner-01, qualys-agent). Additionally, filter out events where the Process Name is identified as a known scanning daemon (e.g., nessus.exe, qualyspcd.exe).
Scenario: Legitimate Cloud Backup and Synchronization Services
- Context: Automated backup agents such as Veeam, Rubrik, or Microsoft Azure Backup frequently establish outbound connections to cloud storage