ThreatFox: SmartApeSG IOCs

Hunt Hypothesis

This hunt detects adversary activity by identifying network connections or file artifacts matching specific Indicators of Compromise (IOCs) linked to the SmartApeSG threat actor. Proactively hunting for these IOCs in Azure Sentinel is critical to rapidly identify early-stage compromises and mitigate potential data exfiltration before the adversary establishes persistence within the environment.

IOC Summary

Malware Family: SmartApeSG Total IOCs: 2 IOC Types: url, domain

KQL: Domain Hunt

// Hunt for DNS queries to known malicious domains
// Source: ThreatFox - SmartApeSG
let malicious_domains = dynamic(["privetbelvedere.net"]);
DnsEvents
| where Name has_any (malicious_domains)
| project TimeGenerated, Computer, Name, IPAddresses, QueryType
| order by TimeGenerated desc

KQL: Url Hunt

// Hunt for access to known malicious URLs
// Source: ThreatFox - SmartApeSG
let malicious_urls = dynamic(["https://privetbelvedere.net/proxy/legacy-thread.js"]);
UrlClickEvents
| where Url has_any (malicious_urls)
| project Timestamp, AccountUpn, Url, ActionType, IsClickedThrough
| order by Timestamp desc

Required Data Sources

References

• ThreatFox — SmartApeSG

False Positive Guidance

Here are 3-5 specific false positive scenarios for the ThreatFox: SmartApeSG IOCs detection rule, including tailored filters and exclusions:

• Scenario: Scheduled Security Tool Updates
  • Context: The enterprise security suite (e.g., CrowdStrike Falcon or Microsoft Defender for Endpoint) automatically downloads definition updates from a vendor repository that shares an IP address or domain with the SmartApeSG IOC list. This often occurs during off-hours maintenance windows.
  • Filter/Exclusion: Create a rule exclusion based on the Process Name and Parent Process. Exclude alerts where the parent process is falcon.sys, MsMpEng.exe, or wuauserv.exe (Windows Update) occurring between 02:00 and 05:00 local time.
• Scenario: Admin-Driven Patch Deployment via Configuration Management
  • Context: During a quarterly patching cycle, the IT Operations team uses Ansible or SCCM (System Center Configuration Manager) to push software updates to endpoints. The deployment server connects to an external artifact repository that matches the SmartApeSG IOCs.
  • Filter/Exclusion: Implement a filter excluding traffic originating from specific internal SCCM distribution points or Ansible control nodes. Add a condition where Source IP belongs to the internal subnet range (e.g., 10.20.x.x) and the destination matches the SmartApeSG IOCs, provided the user context is SYSTEM or a known service account like svc-patch-deploy.
• Scenario: Cloud Backup Agent Connectivity
  • Context: Enterprise backup agents (e.g., Veeam, Rubrik, or Acronis) establish connections to cloud storage gateways. These agents may resolve DNS names that overlap with the SmartApe