This detection rule identifies potential compromise by monitoring for network and host activity matching 103 specific indicators of compromise (IOCs) linked to the Unknown Loader malware family. Proactively hunting for these IOCs in Azure Sentinel is critical because Unknown Loader often serves as a stealthy initial access vector that can establish persistence before triggering broader alerting mechanisms, allowing the SOC team to intercept threats at an early stage.
Malware Family: Unknown Loader Total IOCs: 103 IOC Types: domain
| Type | Value | Threat Type | First Seen | Confidence |
|---|---|---|---|---|
| domain | ytcasinochamp.com | payload_delivery | 2026-08-18 | 75% |
| domain | za-zen.nu | payload_delivery | 2026-08-18 | 75% |
| domain | zavarovanje-osiguranje.eu | payload_delivery | 2026-08-18 | 75% |
| domain | zedpoint.in | payload_delivery | 2026-08-18 | 75% |
| domain | zeny50.cz | payload_delivery | 2026-08-18 | 75% |
| domain | zgsmtrafficlights.com | payload_delivery | 2026-08-18 | 75% |
| domain | zodiacgemstonesgame.com | payload_delivery | 2026-08-18 | 75% |
| domain | zpcou9qu.com | payload_delivery | 2026-08-18 | 75% |
| domain | zspohranicna.sk | payload_delivery | 2026-08-18 | 75% |
| domain | yellowwest.de | payload_delivery | 2026-08-18 | 75% |
| domain | yh5lll.com | payload_delivery | 2026-08-18 | 75% |
| domain | yildirimutu.com | payload_delivery | 2026-08-18 | 75% |
| domain | yolobet.co.uk | payload_delivery | 2026-08-18 | 75% |
| domain | yorcks-kebap.berlin | payload_delivery | 2026-08-18 | 75% |
| domain | younan-aqar.com | payload_delivery | 2026-08-18 | 75% |
| domain | youngbuildingco.com.au | payload_delivery | 2026-08-18 | 75% |
| domain | yourstudypartner.uk | payload_delivery | 2026-08-18 | 75% |
| domain | youssefnaitbelaid.com | payload_delivery | 2026-08-18 | 75% |
| domain | ysinchia.com | payload_delivery | 2026-08-18 | 75% |
| domain | yt54976.cc | payload_delivery | 2026-08-18 | 75% |
| domain | xn--grce-cosmetics-chb.com | payload_delivery | 2026-08-18 | 75% |
| domain | xn--hyvinknkeilaveteraanit-54ba.net | payload_delivery | 2026-08-18 | 75% |
| domain | xn--residenciaenespaa-uxb.es | payload_delivery | 2026-08-18 | 75% |
| domain | xtmetalparts.com | payload_delivery | 2026-08-18 | 75% |
| domain | xxiibet.at | payload_delivery | 2026-08-18 | 75% |
// Hunt for DNS queries to known malicious domains
// Source: ThreatFox - Unknown Loader
let malicious_domains = dynamic(["ytcasinochamp.com", "za-zen.nu", "zavarovanje-osiguranje.eu", "zedpoint.in", "zeny50.cz", "zgsmtrafficlights.com", "zodiacgemstonesgame.com", "zpcou9qu.com", "zspohranicna.sk", "yellowwest.de", "yh5lll.com", "yildirimutu.com", "yolobet.co.uk", "yorcks-kebap.berlin", "younan-aqar.com", "youngbuildingco.com.au", "yourstudypartner.uk", "youssefnaitbelaid.com", "ysinchia.com", "yt54976.cc", "xn--grce-cosmetics-chb.com", "xn--hyvinknkeilaveteraanit-54ba.net", "xn--residenciaenespaa-uxb.es", "xtmetalparts.com", "xxiibet.at", "xxoo330.com", "yakinikubbq.com", "yarasool.org", "ydel.se", "xebervar.net", "xfbusa.com", "xiaozhuikan.net", "xn--80aaucbciik5d5bzg.xn--p1ai", "winnernet.net", "winpokerstar.com", "winwayslotonline.com", "winwiseweekly.com", "wizefelas.co.za", "wizzsale.com", "wmpmng.com", "wmspilhaus.com", "womanlife.co.uk", "woodenproduct.com.ua", "wordress.net", "worldbestcasinostories.com", "wulanstudio.com", "xasesyfejofok.net", "watfordsecurity.co.uk", "wearorastore.com", "web-staging.orchestra-cohort.eu"]);
DnsEvents
| where Name has_any (malicious_domains)
| project TimeGenerated, Computer, Name, IPAddresses, QueryType
| order by TimeGenerated desc
| Sentinel Table | Notes |
|---|---|
DnsEvents | Ensure this data connector is enabled |
Here are 5 specific false positive scenarios for the ThreatFox: Unknown Loader IOCs rule, including suggested filters and exclusions tailored for an enterprise environment:
Legitimate Software Deployment via SCCM/Intune
ccmsetup.exe or msiexec.exe spawning a temporary loader process that downloads and executes an unsigned or newly signed payload, matching the “Unknown Loader” signature before the certificate is fully recognized by ThreatFox.C:\Windows\CCM\* (SCCM) or C:\Program Files\Microsoft Intune Management Extension\*. Additionally, filter out events where the user context is a known service account (e.g., DOMAIN\SCCM-Deploy-Svc) rather than an interactive user.Scheduled Antivirus Definition Updates
FalconSensorService.exe, Symantec Endpoint Protection\Smc.exe, or Windows Defender Service when they are running under a scheduled task (e.g., Task Name: Antivirus Update). Filter based on the specific command line arguments containing keywords like /update, /download, or /install.Internal DevOps Artifact Distribution