ThreatFox: BianLian IOCs

Hunt Hypothesis

The detection identifies potential BianLian malware activity through associated IOCs, indicating possible adversary presence within the network. SOC teams should proactively hunt for this behavior in Azure Sentinel to detect and mitigate advanced persistent threats early.

IOC Summary

Malware Family: BianLian Total IOCs: 2 IOC Types: ip:port

KQL: Ip Hunt

// Hunt for network connections to known malicious IPs
// Source: ThreatFox - BianLian
let malicious_ips = dynamic(["34.123.214.16", "194.213.18.93"]);
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(["34.123.214.16", "194.213.18.93"]);
DeviceNetworkEvents
| where RemoteIP in (malicious_ips)
| project Timestamp, DeviceName, RemoteIP, RemotePort, InitiatingProcessFileName, ActionType
| order by Timestamp desc

Required Data Sources

References

• ThreatFox — BianLian

False Positive Guidance

• Scenario: Legitimate system update using BianLian-associated tools
  Description: A system update or patching process uses a tool like msiexec.exe or setup.exe, which may be flagged due to its association with BianLian.
  Filter/Exclusion: Exclude processes related to known update mechanisms (e.g., msiexec.exe, setup.exe, wusa.exe) or use a filter based on the file path (e.g., C:\Windows\System32\*).

• Scenario: Scheduled job using BianLian-related scripts
  Description: A scheduled task (e.g., via Task Scheduler) runs a script or executable that is falsely associated with BianLian, such as a legitimate maintenance script named clean.exe.
  Filter/Exclusion: Exclude processes initiated by the Task Scheduler (Task Scheduler service) or filter by the command line argument (e.g., --clean or --maintenance).

• Scenario: Admin tool using BianLian IOCs for forensic analysis
  Description: An administrator uses a tool like Process Explorer or Procmon to investigate system behavior, and the tool’s behavior matches the BianLian IOC pattern.
  Filter/Exclusion: Exclude processes from known administrative tools (e.g., procmon.exe, procexp.exe, wbemtest.exe) or filter by user context (e.g., User = Administrator).

• Scenario: Legitimate software installation via MSI package
  Description: A company installs a legitimate software package using an MSI installer, which may contain a file or registry key that matches BianLian IOCs.
  Filter/Exclusion: Exclude processes related to MSI installation (e.g., msiexec.exe) or filter by the file extension (e.g., .msi, .msp).