The Mongal code features rule detects potential obfuscation or encoding techniques used by adversaries to hide malicious payloads within legitimate code structures. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify and mitigate early-stage threats that may evade traditional detection methods.
YARA Rule
rule MongalCode
{
meta:
description = "Mongal code features"
author = "Seth Hardy"
last_modified = "2014-07-15"
strings:
// gettickcount value checking
$ = { 8B C8 B8 D3 4D 62 10 F7 E1 C1 EA 06 2B D6 83 FA 05 76 EB }
condition:
any of them
}
This YARA rule can be deployed in the following contexts:
Scenario: Scheduled System Maintenance Job
Description: A legitimate scheduled job runs to update system configurations or apply patches using tools like systemd, cron, or task scheduler.
Filter/Exclusion: Exclude processes initiated by cron or systemd with known maintenance scripts (e.g., /etc/cron.daily/ or /usr/lib/systemd/system/).
Scenario: Admin Task – User Management via PowerShell
Description: An administrator is performing user account management using PowerShell scripts (e.g., Add-LocalUser, Set-LocalUser).
Filter/Exclusion: Exclude processes with ProcessName = "powershell" and command lines containing Add-LocalUser, Set-LocalUser, or Get-LocalUser.
Scenario: Log File Analysis with ELK Stack
Description: A security analyst is using the ELK stack (Elasticsearch, Logstash, Kibana) to analyze system logs, which may involve parsing and processing log files.
Filter/Exclusion: Exclude processes with ProcessName = "logstash" or ProcessName = "elasticsearch" and filter by known log analysis activities.
Scenario: Software Update via Chocolatey
Description: A system administrator is using Chocolatey to install or update software packages, which may involve executing scripts or commands that resemble malicious activity.
Filter/Exclusion: Exclude processes with ProcessName = "choco" and command lines containing install, update, or upgrade.
Scenario: Database Backup Job via SQL Server Agent
Description: A database backup job is executed via SQL Server Agent, which may involve executing T-SQL scripts that could be misinterpreted as suspicious activity.
Filter/Exclusion: Exclude processes with ProcessName = "sqlservr" and command