This hypothesis targets the presence of known Mirai botnet command-and-control or propagation URLs, indicating active lateral movement or initial access attempts by this prevalent IoT malware family. Proactively hunting for these specific indicators in Azure Sentinel allows the SOC team to identify compromised endpoints or network traffic before the botnet can fully establish its foothold and initiate large-scale scanning or DDoS activities.
Threat: mirai Total URLs: 6 Active URLs: 3
| URL | Status | Threat | Date Added |
|---|---|---|---|
hxxp://3.133.139.254/bot_macos | offline | malware_download | 2026-09-10 |
hxxp://92.119.167.102:8000/arm | online | malware_download | 2026-09-10 |
hxxp://38.55.99.215:8080/moot.x86_64 | online | malware_download | 2026-09-10 |
hxxp://105.225.5.139:52251/i | offline | malware_download | 2026-09-10 |
hxxp://101.108.69.64:50943/i | online | malware_download | 2026-09-10 |
hxxp://105.225.5.139:52251/bin.sh | offline | malware_download | 2026-09-10 |
// Hunt for DNS resolution of URLhaus malicious domains
// Threat: mirai
let malicious_domains = dynamic(["38.55.99.215", "101.108.69.64", "92.119.167.102"]);
DnsEvents
| where Name has_any (malicious_domains)
| project TimeGenerated, Computer, Name, IPAddresses
| order by TimeGenerated desc
// Hunt for web traffic to URLhaus malicious domains
let malicious_domains = dynamic(["38.55.99.215", "101.108.69.64", "92.119.167.102"]);
CommonSecurityLog
| where RequestURL has_any (malicious_domains) or DestinationHostName has_any (malicious_domains)
| project TimeGenerated, SourceIP, RequestURL, DestinationHostName, DeviceAction
| order by TimeGenerated desc
| Sentinel Table | Notes |
|---|---|
CommonSecurityLog | Ensure this data connector is enabled |
DnsEvents | Ensure this data connector is enabled |
IoT Device Firmware Updates via Internal Proxy: Legitimate IoT devices (e.g., IP cameras, smart thermostats, or industrial PLCs) often perform automated firmware checks or updates against known vendor endpoints. If the enterprise uses a transparent proxy or forward proxy that rewrites or caches certain URLs, or if the specific Mirai-tagged URL is a shared CDN endpoint used by a legitimate vendor for asset delivery, the device’s outbound HTTP request may match the rule.
10.50.0.0/16) or specific device MAC addresses from the URL matching logic, provided these devices are inventoried and whitelisted in the CMDB.Web Application Caching and CDN Edge Nodes: In a multi-tier web architecture, internal application servers or API gateways may fetch static assets (CSS, JS, images) from a CDN. If the Mirai-tagged URL corresponds to a popular open-source library or a shared CDN path (e.g., cdnjs.cloudflare.com/...) that is also used by the Mirai botnet for payload delivery, legitimate traffic from internal web servers to the CDN will trigger the alert.
nginx/1.18, Apache/2.4) or where the source is an internal load balancer IP, and verify the Referer header points to an internal domain.Scheduled Backup and Sync Jobs: Enterprise backup solutions (e.g., Veeam, Commvault) or file sync tools (e.g., Synology Drive, Nextcloud) may occasionally connect to external endpoints for license validation, cloud storage API calls, or delta syncs. If one of the Mirai URLs is a generic API endpoint (e