ThreatFox: PureRAT IOCs | SOC Hunt Feed

Hunt Hypothesis

This hunt detects adversary activity involving the PureRAT remote access trojan by monitoring for specific indicators of compromise such as unique file hashes and network connections. Proactively hunting for these signals in Azure Sentinel is critical to identify early-stage lateral movement and command-and-control communications before the malware establishes a persistent foothold within the environment.

IOC Summary

Malware Family: PureRAT Total IOCs: 6 IOC Types: ip:port, domain

Type	Value	Threat Type	First Seen	Confidence
ip:port	`209[.]99[.]190[.]23:45002`	botnet_cc	2026-08-22	75%
ip:port	`209[.]99[.]190[.]23:45003`	botnet_cc	2026-08-22	75%
domain	`scrnmailpsie.com`	botnet_cc	2026-08-22	100%
ip:port	`166[.]88[.]90[.]59:56001`	botnet_cc	2026-08-22	75%
ip:port	`166[.]88[.]90[.]59:56002`	botnet_cc	2026-08-22	75%
ip:port	`166[.]88[.]90[.]59:56003`	botnet_cc	2026-08-22	75%

KQL: Ip Hunt

// Hunt for network connections to known malicious IPs
// Source: ThreatFox - PureRAT
let malicious_ips = dynamic(["209.99.190.23", "166.88.90.59"]);
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(["209.99.190.23", "166.88.90.59"]);
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 - PureRAT
let malicious_domains = dynamic(["scrnmailpsie.com"]);
DnsEvents
| where Name has_any (malicious_domains)
| project TimeGenerated, Computer, Name, IPAddresses, QueryType
| order by TimeGenerated desc

Required Data Sources

Sentinel Table	Notes
`CommonSecurityLog`	Ensure this data connector is enabled
`DeviceNetworkEvents`	Ensure this data connector is enabled
`DnsEvents`	Ensure this data connector is enabled

References

ThreatFox — PureRAT

False Positive Guidance

Here are 5 specific false positive scenarios for the ThreatFox: PureRAT IOCs detection rule, along with suggested filters or exclusions tailored for an enterprise environment:

Scenario: Automated Patch Management Deployment
- Context: Enterprise patching tools (e.g., Microsoft Endpoint Configuration Manager, Ivanti Neurons, or WSUS) frequently download and install security updates that match the specific hash signatures of PureRAT components, particularly if the vendor uses a shared code signing certificate or common library.
- Filter/Exclusion: Exclude alerts where the process name matches known patching executables (e.g., ccmsetup.exe, IvantiAgent.exe) and the parent process is the scheduled task runner (Taskeng.exe or svchost.exe). Additionally, whitelist the specific file hashes if they are confirmed to be part of a standard software update package.
Scenario: Antivirus Engine Scanning and Quarantine
- Context: Endpoint Detection and Response (EDR) agents like CrowdStrike Falcon, SentinelOne, or Microsoft Defender for Endpoint often create temporary copies of files in quarantine folders or scan directories that contain PureRAT IOCs. The detection logic may trigger when the AV engine extracts a known benign file that happens to share an IOC with PureRAT.
- Filter/Exclusion: Filter out events where the source process is a recognized antivirus service (e.g., C:\Program Files\CrowdStrike\csagent.exe or C:\Windows\System32\MsMpEng.exe). Implement a rule to ignore detections occurring within specific quarantine directories (e.g., paths containing \Quarantine\ or \Threats\).
Scenario: Scheduled Remote Management and Backup Jobs
- Context: IT administrators often run scheduled PowerShell scripts