Identify Alina

Hunt Hypothesis

The hypothesis is that the detection rule identifies potential adversarial activity associated with the user or entity named “Alina,” which may indicate unauthorized access or reconnaissance. SOC teams should proactively hunt for this behavior in Azure Sentinel to uncover hidden threats and validate the intent behind suspicious user activity.

YARA Rule

rule alina
{
	meta:
		author = "Brian Wallace @botnet_hunter"
		author_email = "[email protected]"
		date = "2014-08-09"
		description = "Identify Alina"
	strings:
		$s1 = "Alina v1.0"
		$s2 = "POST"
		$s3 = "1[0-2])[0-9]"

	condition:
        	all of them
}

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

This rule contains 3 string patterns in its detection logic.

• Source Rule

False Positive Guidance

• Scenario: Alina is a legitimate user running a scheduled backup job using Veeam Backup & Replication.
  Filter/Exclusion: Exclude activity related to veeambackup or backup tasks executed by the user “Alina” during scheduled maintenance windows.

• Scenario: Alina is a system administrator performing routine Windows Task Scheduler maintenance, such as updating system logs or running disk cleanup.
  Filter/Exclusion: Exclude tasks associated with Task Scheduler or schtasks.exe executed by the user “Alina” during off-peak hours.

• Scenario: Alina is a developer using Git to push code to a remote repository, which may trigger system-level monitoring.
  Filter/Exclusion: Exclude Git-related processes (git.exe, ssh.exe) initiated by the user “Alina” during development hours.

• Scenario: Alina is a database administrator using SQL Server Management Studio (SSMS) to run maintenance scripts or backups.
  Filter/Exclusion: Exclude SQL Server processes (sqlservr.exe, ssms.exe) initiated by the user “Alina” during scheduled database maintenance windows.

• Scenario: Alina is a security analyst using Splunk to investigate potential threats, which may involve querying logs or running searches.
  Filter/Exclusion: Exclude Splunk-related processes (splunkd.exe, splunksearch.exe) initiated by the user “Alina” during active investigation periods.