ThreatFox: SmartApeSG IOCs

Hunt Hypothesis

This hunt detects adversary activity involving specific indicators of compromise (IOCs) linked to the SmartApeSG threat actor, which may signal early-stage reconnaissance or lateral movement within the network. Proactively hunting for these IOCs in Azure Sentinel is critical to identify potential high-severity threats before they escalate into active breaches, ensuring timely containment and response.

IOC Summary

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

KQL: Domain Hunt

// Hunt for DNS queries to known malicious domains
// Source: ThreatFox - SmartApeSG
let malicious_domains = dynamic(["indigocrest.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://indigocrest.top/middleware/scope-runtime.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 for the ThreatFox: SmartApeSG IOCs rule, including targeted filters and exclusions tailored for an enterprise environment:

• Scenario: Legitimate Endpoint Detection & Response (EDR) Telemetry Uploads

  • Context: Enterprise EDR agents (e.g., CrowdStrike Falcon or Microsoft Defender for Endpoint) periodically upload threat intelligence feeds to their cloud management consoles. If the SmartApeSG IOCs include specific IP addresses or domains used by these vendors’ update servers, the rule may trigger on routine telemetry uploads rather than malicious activity.
  • Filter/Exclusion: Create a filter in the SIEM (e.g., Splunk or Sentinel) to exclude traffic where Source_Process_Name matches known EDR agents (FalconSensor.exe, MsMpEng.exe) AND Destination_Port is 443, provided the destination IP belongs to the vendor’s trusted CIDR range.

• Scenario: Scheduled Third-Party Vulnerability Scanner Jobs

  • Context: Automated vulnerability management tools (e.g., Tenable Nessus or Qualys) run nightly scans against internal assets. If SmartApeSG IOCs include a domain used by the scanner’s update repository, the rule will trigger when the scanner downloads new plugin definitions or vulnerability signatures during its scheduled maintenance window (e.g., 02:00–04:00 UTC).
  • Filter/Exclusion: Implement an exclusion based on Source_Host_Group containing “Vulnerability_Scan_Nodes” and restrict the rule to trigger only outside of the defined maintenance window (e.g., exclude events occurring between 01:00 and 05:00).

• Scenario: Admin-Driven Software Deployment via Configuration Management

  • Context: System administrators use tools like SCCM or