ThreatFox: Vidar IOCs

Hunt Hypothesis

This rule detects the presence of Vidar, a credential-stealing malware known for harvesting sensitive data such as browser passwords and cryptocurrency wallet keys from compromised endpoints. Proactively hunting for these IOCs in Azure Sentinel is critical to identify and isolate infected hosts before the adversary exfiltrates credentials, thereby preventing lateral movement and persistent access within the environment.

IOC Summary

Malware Family: Vidar Total IOCs: 5 IOC Types: url, domain

KQL: Domain Hunt

// Hunt for DNS queries to known malicious domains
// Source: ThreatFox - Vidar
let malicious_domains = dynamic(["hj.234-e.com", "hj.1jp88.org"]);
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 - Vidar
let malicious_urls = dynamic(["https://hj.1jp88.org/", "https://hj.234-e.com/", "https://172.236.209.126"]);
UrlClickEvents
| where Url has_any (malicious_urls)
| project Timestamp, AccountUpn, Url, ActionType, IsClickedThrough
| order by Timestamp desc

Required Data Sources

References

• ThreatFox — Vidar

False Positive Guidance

• Scenario: A DevOps engineer uses a legitimate credential management tool (e.g., CyberArk, HashiCorp Vault, or a custom Python script using pywin32) to retrieve and store service account passwords in a secure database during a scheduled nightly backup job.
  • Filter/Exclusion: Exclude processes where the parent process is a known service manager (e.g., svchost.exe hosting a specific service, or python.exe running from a specific CI/CD agent directory) and the target module is a known secure library (e.g., crypt32.dll or bcrypt.dll) rather than generic memory scanning APIs.
• Scenario: An IT administrator runs a standard Windows utility like procdump or Sysinternals tools to troubleshoot a hung application, which may involve reading process memory or enumerating modules to diagnose the issue.
  • Filter/Exclusion: Exclude executions where the binary path matches known Sysinternals directories (e.g., C:\Sysinternals\) or where the process name is procdump.exe, procmon.exe, or procexp.exe, and the action is limited to read-only memory access without subsequent network exfiltration.
• Scenario: A security team performs a live response or forensic triage using tools like Volatility or Eric Zimmerman’s APEX to analyze a suspect host, which inherently involves scanning process memory for credentials and artifacts.
  • Filter/Exclusion: Exclude processes running from specific forensic tool directories (e.g., C:\Forensics\Volatility\) or where the user account belongs to the SecurityTeam or Forensics group, and the process is initiated by an interactive user session rather than a service account.
• Scenario: A Java or .NET application (e.g., a legacy