ThreatFox: SmartApeSG IOCs

Hunt Hypothesis

This hunt targets adversary behavior involving known indicators of compromise from the SmartApeSG threat actor to identify potential lateral movement or initial access within the network. Proactively hunting for these specific IOCs in Azure Sentinel is critical because early detection of this high-severity threat enables rapid containment before the adversary establishes persistence or exfiltrates sensitive data.

IOC Summary

Malware Family: SmartApeSG Total IOCs: 6 IOC Types: domain, url

KQL: Domain Hunt

// Hunt for DNS queries to known malicious domains
// Source: ThreatFox - SmartApeSG
let malicious_domains = dynamic(["marblecourier.top", "cedarfrontier.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://marblecourier.top/rate/login-cache.js", "https://cedarfrontier.top/token/tenant-thread.js", "https://cedarfrontier.top/token/api-view", "https://cedarfrontier.top/token/signup-controller.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 5 specific false positive scenarios for the ThreatFox: SmartApeSG IOCs detection rule in an enterprise environment, along with suggested filters and exclusions:

• Scenario: Enterprise Antivirus Signature Updates

  • Context: The organization’s endpoint protection solution (e.g., CrowdStrike Falcon or Microsoft Defender for Endpoint) performs scheduled definition updates. These updates often download and execute temporary installer scripts or DLLs that match the hash patterns of SmartApeSG legitimate components used in third-party software libraries.
  • Filter/Exclusion: Create an exclusion rule based on the Process Name (e.g., C:\Program Files\CrowdStrike\csagent.exe) and restrict the alert to only trigger if the parent process is not a known security vendor executable. Alternatively, whitelist specific SHA-256 hashes of the update installer packages used by your EDR solution.

• Scenario: Automated Patch Management Execution

  • Context: During the monthly maintenance window, the IT team runs Microsoft SCCM (Configuration Manager) or Ivanti Endpoint Manager to deploy application patches. These tools frequently extract and execute temporary deployment agents that contain IOCs overlapping with SmartApeSG’s legitimate file signatures before cleaning up the temp folders.
  • Filter/Exclusion: Implement a time-based filter to suppress alerts during known maintenance windows (e.g., 02:00 - 04:00 UTC). Additionally, exclude processes spawned by specific service accounts used for patching, such as DOMAIN\svc-patch-deploy or SYSTEM, when the execution path is within the standard software distribution directory (e.g., C:\Windows\CCMCache).

• Scenario: Internal Software Deployment via Package Managers

  • Context: The DevOps team utilizes Chocolatey or **Ans