ThreatFox: SmartApeSG IOCs

Hunt Hypothesis

This hunt hypothesis detects adversary activity involving specific indicators of compromise (IOCs) linked to the SmartApeSG threat actor by monitoring network and endpoint logs against known malicious signatures. The SOC team should proactively hunt for these IOCs in Azure Sentinel to identify early-stage intrusions from this high-severity threat, enabling rapid containment before lateral movement or data exfiltration occurs.

IOC Summary

Malware Family: SmartApeSG Total IOCs: 2 IOC Types: ip:port, domain

KQL: Ip Hunt

// Hunt for network connections to known malicious IPs
// Source: ThreatFox - SmartApeSG
let malicious_ips = dynamic(["178.156.164.194"]);
CommonSecurityLog
| where DestinationIP in (malicious_ips) or SourceIP in (malicious_ips)
| project TimeGenerated, SourceIP, DestinationIP, DestinationPort, DeviceAction, Activity
| order by TimeGenerated desc

KQL: Ip Hunt Device

// Hunt in Defender for Endpoint network events
let malicious_ips = dynamic(["178.156.164.194"]);
DeviceNetworkEvents
| where RemoteIP in (malicious_ips)
| project Timestamp, DeviceName, RemoteIP, RemotePort, InitiatingProcessFileName, ActionType
| order by Timestamp desc

KQL: Domain Hunt

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

Required Data Sources

References

• ThreatFox — SmartApeSG

False Positive Guidance

Here are 4 specific false positive scenarios for the ThreatFox: SmartApeSG IOCs detection rule, along with targeted filters and exclusions suitable for an enterprise environment:

• Endpoint Protection Policy Updates via CrowdStrike Falcon

  • Scenario: The CrowdStrike Falcon Sensor pushes updated threat intelligence feeds containing SmartApeSG signatures to all endpoints. This triggers the rule when the sensor downloads or validates these specific IOCs during its scheduled daily update cycle (e.g., 02:00 UTC).
  • Filter/Exclusion: Exclude network traffic and process execution events where the source application is C:\Program Files\CrowdStrike\FalconSensor\csfalcon.exe and the destination IP matches the known CrowdStrike update servers. Alternatively, add a time-based suppression for this rule between 01:00 and 04:00 UTC on weekdays.

• Automated Threat Intel Ingestion by Splunk Enterprise Security

  • Scenario: The SIEM’s scheduled job (e.g., threat_intel_import.py) ingests a daily CSV feed from an external vendor that includes SmartApeSG indicators. When the parser processes these records, it generates events matching the rule’s logic before the data is fully normalized and correlated with other context.
  • Filter/Exclusion: Create a filter to exclude events where the source_app field equals Splunk Enterprise AND the event_type contains “IOC Import”. Additionally, suppress alerts if the event occurs within the specific ingestion window (e.g., 09:00–10:30 local time) and the user context is a service account like svc-siem-integration.

• Scheduled Scans by Microsoft Defender for Endpoint

  • Scenario: During the weekly full system scan, Microsoft Defender queries its cloud intelligence service to cross-reference