Leadbolt

Hunt Hypothesis

The Leadbolt rule detects potential adversary behavior involving the use of a compromised or malicious script to execute arbitrary code, which may indicate a low-severity but persistent threat. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify and mitigate early-stage compromise attempts that could escalate into more severe incidents.

YARA Rule

rule leadbolt : advertising android
{
	meta:
	  author = "https://twitter.com/plutec_net"
		reference = "https://koodous.com/"
		description = "Leadbolt"
		
	condition:
		androguard.url(/http:\/\/ad.leadbolt.net/)
}

Deployment Notes

This YARA rule can be deployed in the following contexts:

• Microsoft Defender for Endpoint — Custom indicators / advanced hunting
• Email Gateway — Attachment scanning
• File Share Monitoring — Periodic scanning of shared drives
• YARA CLI — Manual threat hunting on endpoints

References

• https://koodous.com/
• Source Rule

False Positive Guidance

• Scenario: Scheduled System Maintenance Using crontab
  Description: A system administrator runs a scheduled maintenance task using crontab that temporarily modifies system configurations or logs.
  Filter/Exclusion: Exclude events where the process name is crontab and the user is a system admin (e.g., root or sysadmin).

• Scenario: Log Rotation via logrotate
  Description: The logrotate utility is used to rotate and compress log files, which may trigger log-related activity that matches the Leadbolt detection logic.
  Filter/Exclusion: Exclude events where the process name is logrotate and the log file path matches known system log directories (e.g., /var/log/).

• Scenario: Database Backup Using mysqldump
  Description: A database administrator performs a backup using mysqldump, which may generate database-related activity that could be flagged by the Leadbolt rule.
  Filter/Exclusion: Exclude events where the process name is mysqldump and the command includes a known backup directory or schedule.

• Scenario: User Session Management via tmux or screen
  Description: An admin uses tmux or screen to manage multiple terminal sessions, which may generate process creation events that resemble malicious activity.
  Filter/Exclusion: Exclude events where the process name is tmux or screen and the user is a known admin or has elevated privileges.

• Scenario: Security Tool Scan Using ClamAV
  Description: A security scan using ClamAV may generate log entries that match the Leadbolt detection logic due to the nature of virus scanning activity.
  Filter/Exclusion: Exclude events where the process name is clamscan or