Decoding LAPSUS$: Unraveling the Threat through Threat Hunting

As the cybersecurity landscape continues to evolve, threat actors are constantly developing new and sophisticated attack techniques. Among these threats, LAPSUS$ has emerged as a formidable adversary, known for its targeted attacks and disruptive capabilities. As LAPSUS$ poses a significant risk to organizations worldwide, proactive threat hunting becomes paramount to identify and neutralize this insidious threat. In this blog, we will embark on a journey of threat hunting for LAPSUS$ malware, featuring real-world examples, Splunk queries, and YARA rules to help organizations fortify their defenses against this elusive and dangerous menace.

LAPSUS$ is a highly advanced and stealthy malware that primarily targets financial institutions and high-profile organizations. It typically spreads through spear-phishing campaigns and malicious attachments, enabling the attackers to gain a foothold within the targeted network. Once inside, LAPSUS$ can perform a range of malicious activities, including data exfiltration, credential theft, and lateral movement to escalate privileges.

Let’s explore practical threat hunting examples to detect and respond to LAPSUS$ malware:

Example 1: Unusual Process Execution
Hunt for unusual process execution patterns on endpoints.

index=main sourcetype=”WinEventLog:Security” EventCode=4688 earliest=-1w

Look for processes launched from uncommon locations or with suspicious names.

Example 2: Lateral Movement
Monitor for lateral movement attempts within the network.

index=main sourcetype=”WinEventLog:Security” (EventCode=4624 OR EventCode=4625) earliest=-1w

Look for multiple login attempts from different systems, which could indicate lateral movement by the attacker.

YARA rules offer a powerful way to create custom signatures for detecting LAPSUS$ malware. Let’s create a YARA rule for LAPSUS$:

rule LAPSUS_Malware {
meta:
description = “Detects LAPSUS$ malware files”
strings:
$magic = { 4D 5A } // MZ (DOS/Windows executable)
$pattern = “LAPSUS$” // Unique string indicative of LAPSUS$
condition:
$magic at 0 and $pattern
}

Leverage Splunk for endpoint and network monitoring to detect potential LAPSUS$ infections:

# Endpoint Activity Monitoring
index=main sourcetype=”WinEventLog:Security” EventCode=4688
| search New_Process_Name=”*.exe” OR New_Process_Name=”*.dll”

# Network Activity Monitoring
index=network earliest=-1w
| rex field=_raw “Host=(?<dest_host>[^\s]+)”
| rex field=_raw “User_Agent=(?<user_agent>[^\s]+)”
| search dest_host=”*.onion” OR user_agent=”LAPSUS$”

Threat hunting is a critical practice to stay ahead of the elusive and sophisticated LAPSUS$ malware. By employing Splunk queries and YARA rules, organizations can enhance their detection capabilities, identify suspicious activities, and respond swiftly to LAPSUS$ threats. Continuous monitoring and collaboration with the cybersecurity community are essential to stay ahead of LAPSUS$’s rapidly evolving tactics. Implementing these strategies will fortify your organization’s cybersecurity defenses, ensuring resilience against LAPSUS$ and other advanced malware strains. Remember, a vigilant and proactive approach to threat hunting is the key to unraveling LAPSUS$’s threat and safeguarding your network from its destructive reach. Happy hunting!

(Note: The examples provided in this blog are intended for illustrative purposes only and may require customization based on the specific environment and requirements of individual organizations.)