Application Shimming

Detection Strategy for Application Shimming via sdbinst.exe and Registry Artifacts (Windows)

User Account Control: User Account Control (UAC) is a security feature in Microsoft Windows that prevents unauthorized changes to the operating system. UAC prompts users to confirm or provide administrator credentials when an action requires elevated privileges. Proper configuration of UAC reduces the risk of privilege escalation attacks. This mitigation can be implemented through the following measures:

Enable UAC Globally:

• Ensure UAC is enabled through Group Policy by setting User Account Control: Run all administrators in Admin Approval Mode to Enabled.

Require Credential Prompt:

• Use Group Policy to configure UAC to prompt for administrative credentials instead of just confirmation (User Account Control: Behavior of the elevation prompt).

Restrict Built-in Administrator Account:

Set Admin Approval Mode for the built-in Administrator account to Enabled in Group Policy.

Secure the UAC Prompt:

• Configure UAC prompts to display on the secure desktop (User Account Control: Switch to the secure desktop when prompting for elevation).

Prevent UAC Bypass:

• Block untrusted applications from triggering UAC prompts by configuring User Account Control: Only elevate executables that are signed and validated.
• Use EDR tools to detect and block known UAC bypass techniques.

Monitor UAC-Related Events:

• Use Windows Event Viewer to monitor for event ID 4688 (process creation) and look for suspicious processes attempting to invoke UAC elevation.

Tools for Implementation

Built-in Windows Tools:

• Group Policy Editor: Configure UAC settings centrally for enterprise environments.
• Registry Editor: Modify UAC-related settings directly, such as EnableLUA and ConsentPromptBehaviorAdmin.

Endpoint Security Solutions:

• Microsoft Defender for Endpoint: Detects and blocks UAC bypass techniques.
• Sysmon: Logs process creations and monitors UAC elevation attempts for suspicious activity.

Third-Party Security Tools:

• Process Monitor (Sysinternals): Tracks real-time processes interacting with UAC.
• EventSentry: Monitors Windows Event Logs for UAC-related alerts.

Update Software: Software updates ensure systems are protected against known vulnerabilities by applying patches and upgrades provided by vendors. Regular updates reduce the attack surface and prevent adversaries from exploiting known security gaps. This includes patching operating systems, applications, drivers, and firmware. This mitigation can be implemented through the following measures:

Regular Operating System Updates

• Implementation: Apply the latest Windows security updates monthly using WSUS (Windows Server Update Services) or a similar patch management solution. Configure systems to check for updates automatically and schedule reboots during maintenance windows.
• Use Case: Prevents exploitation of OS vulnerabilities such as privilege escalation or remote code execution.

Application Patching

• Implementation: Monitor Apache's update release notes for security patches addressing vulnerabilities. Schedule updates for off-peak hours to avoid downtime while maintaining security compliance.
• Use Case: Prevents exploitation of web application vulnerabilities, such as those leading to unauthorized access or data breaches.

Firmware Updates

• Implementation: Regularly check the vendor’s website for firmware updates addressing vulnerabilities. Plan for update deployment during scheduled maintenance to minimize business disruption.
• Use Case: Protects against vulnerabilities that adversaries could exploit to gain access to network devices or inject malicious traffic.

Emergency Patch Deployment

• Implementation: Use the emergency patch deployment feature of the organization's patch management tool to apply updates to all affected Exchange servers within 24 hours.
• Use Case: Reduces the risk of exploitation by rapidly addressing critical vulnerabilities.

Centralized Patch Management

• Implementation: Implement a centralized patch management system, such as SCCM or ManageEngine, to automate and track patch deployment across all environments. Generate regular compliance reports to ensure all systems are updated.
• Use Case: Streamlines patching processes and ensures no critical systems are missed.

Tools for Implementation

Patch Management Tools:

• WSUS: Manage and deploy Microsoft updates across the organization.
• ManageEngine Patch Manager Plus: Automate patch deployment for OS and third-party apps.
• Ansible: Automate updates across multiple platforms, including Linux and Windows.

Vulnerability Scanning Tools:

• OpenVAS: Open-source vulnerability scanning to identify missing patches.