ThreatFox: TonRAT IOCs

Hunt Hypothesis

This hunt detects adversary behavior involving the deployment of TonRAT malware by identifying six specific indicators of compromise that signal active remote access trojan infections within the environment. A SOC team should proactively hunt for these IOCs in Azure Sentinel to rapidly identify and contain potential data exfiltration or lateral movement attacks before they escalate into broader security incidents.

IOC Summary

Malware Family: TonRAT Total IOCs: 6 IOC Types: domain

KQL: Domain Hunt

// Hunt for DNS queries to known malicious domains
// Source: ThreatFox - TonRAT
let malicious_domains = dynamic(["photohub-vault.info", "photosafe-docs.info", "safevisa-hub.info", "secure-picstore.info", "securehub-4pics.info", "vault-picstore.info"]);
DnsEvents
| where Name has_any (malicious_domains)
| project TimeGenerated, Computer, Name, IPAddresses, QueryType
| order by TimeGenerated desc

Required Data Sources

References

• ThreatFox — TonRAT

False Positive Guidance

Here are 5 specific false positive scenarios for the ThreatFox: TonRAT IOCs detection rule, along with targeted filters and exclusions suitable for an enterprise environment:

• Scenario: Legitimate Admin Script Execution via PowerShell

  • Context: System administrators frequently run custom PowerShell scripts to manage user accounts or patch deployments. These scripts often download configuration files from internal repositories that share the same hash or URL patterns as TonRAT IOCs (e.g., specific SHA-256 hashes for common library dependencies).
  • Filter/Exclusion: Create a detection rule exclusion based on the ProcessName being powershell.exe and the CommandLine containing keywords like -ExecutionPolicy Bypass or internal domain paths (e.g., *.corp.local). Additionally, whitelist specific SHA-256 hashes known to be used in standard admin toolkits.

• Scenario: Scheduled Backup Jobs Utilizing Cloud Storage

  • Context: Enterprise backup solutions (such as Veeam or Commvault) often schedule nightly jobs that upload logs and metadata to cloud storage endpoints. These uploads may trigger network alerts if the destination IP range overlaps with TonRAT’s known command-and-control (C2) infrastructure, especially if both use similar port ranges (e.g., 443).
  • Filter/Exclusion: Exclude traffic originating from specific backup service accounts (e.g., DOMAIN\BackupSvc) or restrict the alert to exclude source IP ranges dedicated to the Data Center. Implement a filter where SourceProcess matches known backup executables like vbr.exe or commvaultagent.

• Scenario: Endpoint Protection Scanner Updates

  • Context: Antivirus solutions (e.g., CrowdStrike Falcon, Microsoft Defender for Endpoint) periodically download definition updates and threat intelligence feeds. The update servers may share IP addresses or file signatures with