ThreatFox: N-W0rm IOCs

Hunt Hypothesis

This detection rule identifies the lateral movement and data exfiltration activities of the N-W0rm malware as it propagates through network segments while establishing command-and-control channels. A proactive hunt for these indicators in Azure Sentinel is critical to rapidly contain the worm’s spread and prevent significant data loss before it compromises additional assets across the environment.

IOC Summary

Malware Family: N-W0rm Total IOCs: 2 IOC Types: ip:port

KQL: Ip Hunt

// Hunt for network connections to known malicious IPs
// Source: ThreatFox - N-W0rm
let malicious_ips = dynamic(["178.66.70.14", "188.32.41.18"]);
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(["178.66.70.14", "188.32.41.18"]);
DeviceNetworkEvents
| where RemoteIP in (malicious_ips)
| project Timestamp, DeviceName, RemoteIP, RemotePort, InitiatingProcessFileName, ActionType
| order by Timestamp desc

Required Data Sources

References

• ThreatFox — N-W0rm

False Positive Guidance

Here are 5 specific false positive scenarios for the ThreatFox: N-W0rm IOCs detection rule, including suggested filters or exclusions tailored for an enterprise environment:

• Scheduled Antivirus Definition Updates via Cloud Sync

  • Scenario: Enterprise endpoints running Microsoft Defender for Endpoint or CrowdStrike Falcon automatically download and install daily definition updates. These processes often initiate lateral network connections to cloud repositories that match the N-W0rm C2 IP ranges or file hash signatures, triggering alerts when the update service scans internal shares.
  • Filter/Exclusion: Create a rule exclusion based on the specific process names of the AV agents (e.g., MsMpEng.exe, FalconSensorService.exe) and exclude traffic originating from known update server subnets or whitelisted cloud IP ranges defined in the threat intelligence feed.

• Enterprise File Share Replication Jobs

  • Scenario: Automated nightly replication jobs using Robocopy, rsync, or Veeam Backup & Replication agents traverse the network to synchronize data between file servers (e.g., Windows Server 2019/2022). These jobs generate high-volume lateral traffic and temporary file creation patterns that mimic the worm’s propagation behavior, especially when accessing shared folders with similar naming conventions.
  • Filter/Exclusion: Exclude alerts where the source process is a known backup or replication service (e.g., VeeamTransport.exe, rsyncd) and the destination port corresponds to standard file transfer protocols (SMB 445, SSH 22) during defined maintenance windows (e.g., 01:00 – 05:00 local time).

• Software Deployment via Configuration Management Tools

  • Scenario: The IT Operations team uses Microsoft SCCM (Configuration Manager) or **