Analytics Story: Meduza Stealer

Date: 2024-11-28 ID: c3328a8a-565b-435e-b9cc-5410e34b821b Author: Teoderick Contreras, Splunk Product: Splunk Enterprise Security

Description

Meduza Stealer is a sophisticated and rapidly evolving malware designed to extract sensitive data from compromised systems. Detected primarily through anomalous network activities, its behavior often involves outbound connections to command-and-control (C2) servers, encrypting and exfiltrating stolen credentials, financial data, and other personal information. Analysts have identified Meduza Stealer leveraging advanced evasion techniques, including dynamic obfuscation, anti-analysis methods, and the use of polymorphic code to bypass detection by traditional antivirus systems. Once deployed, it scans for browser-stored passwords, cryptocurrency wallets, and keylogging opportunities, potentially exploiting unpatched software vulnerabilities. Security tools flag it through heuristic detections, anomalous process executions, or unusual registry modifications. Meduza Stealer's malicious payloads are often distributed via phishing emails, malicious attachments, or trojanized software downloads. Effective defense requires a multi-layered security approach, regular software updates, and employee training to minimize risks posed by this potent cyber threat.

Why it matters

Meduza Stealer is a relatively new entrant in the cybercrime landscape, first identified in early 2023. It quickly gained notoriety among threat actors for its effectiveness and adaptability. Designed as a data-stealing malware, it targets sensitive information such as login credentials, financial details, and cryptocurrency wallets. Its developers market it on underground forums, often touting its advanced features like dynamic obfuscation and anti-analysis mechanisms, making it difficult for traditional antivirus solutions to detect. Meduza Stealer typically spreads through phishing campaigns, malicious email attachments, and trojanized software downloads. Once executed, it infiltrates systems silently, harvesting data from web browsers, password managers, and clipboard activities. It then transmits the stolen information to its command-and-control (C2) servers using encrypted communication channels, further complicating detection and analysis. Security researchers have noted its use of polymorphic code, enabling it to modify its structure with each infection to evade heuristic and signature-based detection methods.Meduza Stealer highlights a growing trend in sophisticated, modular malware that appeals to cybercriminals due to its efficiency and ease of deployment. Effective mitigation strategies include adopting behavioral analysis tools, implementing robust endpoint security solutions, and maintaining user awareness through regular cybersecurity training. Proactive measures are essential to combat the escalating threat posed by this advanced malware.

Detections

Name ▲▼	Technique ▲▼	Type ▲▼
Detect Outlook exe writing a zip file	Phishing, Spearphishing Attachment	TTP
Executables Or Script Creation In Suspicious Path	Masquerading	Anomaly
Ping Sleep Batch Command	Virtualization/Sandbox Evasion, Time Based Evasion	Anomaly
Suspicious Process DNS Query Known Abuse Web Services	Visual Basic, Command and Scripting Interpreter	TTP
Suspicious Process File Path	Create or Modify System Process	TTP
Windows Access Token Manipulation SeDebugPrivilege	Create Process with Token, Access Token Manipulation	Anomaly
Windows Credential Access From Browser Password Store	Query Registry	Anomaly
Windows Credentials Access via VaultCli Module	Windows Credential Manager	Anomaly
Windows Credentials from Password Stores Chrome Extension Access	Query Registry	Anomaly
Windows Credentials from Password Stores Chrome LocalState Access	Query Registry	Anomaly
Windows Credentials from Password Stores Chrome Login Data Access	Query Registry	Anomaly
Windows Gather Victim Network Info Through Ip Check Web Services	IP Addresses, Gather Victim Network Information	Hunting
Windows Query Registry UnInstall Program List	Query Registry	Anomaly
Windows Unsecured Outlook Credentials Access In Registry	Unsecured Credentials	Anomaly

Data Sources

Name ▲▼	Platform ▲▼	Sourcetype ▲▼	Source ▲▼
CrowdStrike ProcessRollup2	N/A	`crowdstrike:events:sensor`	`crowdstrike`
Sysmon EventID 1	Windows	`xmlwineventlog`	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`
Sysmon EventID 11	Windows	`xmlwineventlog`	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`
Sysmon EventID 22	Windows	`xmlwineventlog`	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`
Windows Event Log Security 4663	Windows	`xmlwineventlog`	`XmlWinEventLog:Security`
Windows Event Log Security 4688	Windows	`xmlwineventlog`	`XmlWinEventLog:Security`
Windows Event Log Security 4703	Windows	`xmlwineventlog`	`XmlWinEventLog:Security`

References

Source: GitHub | Version: 1