ThreatFox: SmartApeSG IOCs

Hunt Hypothesis

This detection rule identifies adversary activity by monitoring network and endpoint logs for specific indicators of compromise (IOCs) linked to the SmartApeSG threat actor. Proactively hunting for these IOCs in Azure Sentinel is critical because early identification of this high-severity campaign enables rapid containment before adversaries can establish persistence or exfiltrate sensitive data.

IOC Summary

Malware Family: SmartApeSG Total IOCs: 8 IOC Types: url, domain

KQL: Domain Hunt

// Hunt for DNS queries to known malicious domains
// Source: ThreatFox - SmartApeSG
let malicious_domains = dynamic(["slatebeacon.top", "ivyprologue.top"]);
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://slatebeacon.top/legacy/throttle-theme.js", "https://slatebeacon.top/legacy/identity-build", "https://slatebeacon.top/legacy/version-validator.js", "https://ivyprologue.top/legacy/throttle-theme.js", "https://ivyprologue.top/legacy/identity-build", "https://ivyprologue.top/legacy/version-validator.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 4 specific false positive scenarios and corresponding exclusion strategies for the ThreatFox: SmartApeSG IOCs detection rule in an enterprise environment:

• Scenario: Scheduled Antivirus Definition Updates

  • Context: The endpoint protection suite (e.g., CrowdStrike Falcon or Microsoft Defender for Endpoint) performs nightly definition updates. These updates often pull signature files from the vendor’s cloud repository, which may share IP ranges or hash values with the SmartApeSG IOCs if they utilize similar CDN infrastructure or shared certificate authorities.
  • Filter/Exclusion: Create a time-based exclusion allowing traffic to the specific update server IPs during the maintenance window (e.g., 02:00 – 04:00 UTC). Alternatively, exclude the process falcon.sys (CrowdStrike) or MsMpEng.exe (Defender) when connecting to these IOCs.

• Scenario: Automated Cloud Backup Jobs

  • Context: Enterprise backup solutions like Veeam Backup & Replication or Rubrik run scheduled jobs that initiate connections to external S3 buckets or cloud storage gateways. If the SmartApeSG IOCs include a specific DNS name or IP range used by these storage providers, legitimate backup traffic will trigger alerts.
  • Filter/Exclusion: Exclude network flows where the source process is VeeamBackupService.exe or rubrik-agent.exe. Additionally, add the specific destination IP ranges associated with the organization’s cloud storage provider to the rule’s allow-list if they overlap with SmartApeSG data.

• Scenario: Third-Party SaaS Integration Sync

  • Context: Business applications such as Salesforce, ServiceNow, or Workday run continuous synchronization jobs (e.g., nightly user provisioning or CRM data replication). These integr