Dynamic Linker Hijacking

Detection Strategy for Hijack Execution Flow: Dynamic Linker Hijacking

Operating System Configuration: Operating System Configuration involves adjusting system settings and hardening the default configurations of an operating system (OS) to mitigate adversary exploitation and prevent abuse of system functionality. Proper OS configurations address security vulnerabilities, limit attack surfaces, and ensure robust defense against a wide range of techniques. This mitigation can be implemented through the following measures:

Disable Unused Features:

• Turn off SMBv1, LLMNR, and NetBIOS where not needed.
• Disable remote registry and unnecessary services.

Enforce OS-level Protections:

• Enable Data Execution Prevention (DEP), Address Space Layout Randomization (ASLR), and Control Flow Guard (CFG) on Windows.
• Use AppArmor or SELinux on Linux for mandatory access controls.

Secure Access Settings:

• Enable User Account Control (UAC) for Windows.
• Restrict root/sudo access on Linux/macOS and enforce strong permissions using sudoers files.

File System Hardening:

• Implement least-privilege access for critical files and system directories.
• Audit permissions regularly using tools like icacls (Windows) or getfacl/chmod (Linux/macOS).

Secure Remote Access:

• Restrict RDP, SSH, and VNC to authorized IPs using firewall rules.
• Enable NLA for RDP and enforce strong password/lockout policies.

Harden Boot Configurations:

• Enable Secure Boot and enforce UEFI/BIOS password protection.
• Use BitLocker or LUKS to encrypt boot drives.

Regular Audits:

• Periodically audit OS configurations using tools like CIS Benchmarks or SCAP tools.

Tools for Implementation

Windows:

• Microsoft Group Policy Objects (GPO): Centrally enforce OS security settings.
• Windows Defender Exploit Guard: Built-in OS protection against exploits.
• CIS-CAT Pro: Audit Windows security configurations based on CIS Benchmarks.

Linux/macOS:

• AppArmor/SELinux: Enforce mandatory access controls.
• Lynis: Perform comprehensive security audits.
• SCAP Security Guide: Automate configuration hardening using Security Content Automation Protocol.

Cross-Platform:

• Ansible or Chef/Puppet: Automate configuration hardening at scale.
• OpenSCAP: Perform compliance and configuration checks.

Execution Prevention: Prevent the execution of unauthorized or malicious code on systems by implementing application control, script blocking, and other execution prevention mechanisms. This ensures that only trusted and authorized code is executed, reducing the risk of malware and unauthorized actions. This mitigation can be implemented through the following measures:

Application Control:

• Use Case: Use tools like AppLocker or Windows Defender Application Control (WDAC) to create whitelists of authorized applications and block unauthorized ones. On Linux, use tools like SELinux or AppArmor to define mandatory access control policies for application execution.
• Implementation: Allow only digitally signed or pre-approved applications to execute on servers and endpoints. (e.g., New-AppLockerPolicy -PolicyType Enforced -FilePath "C:\Policies\AppLocker.xml")

Script Blocking:

• Use Case: Use script control mechanisms to block unauthorized execution of scripts, such as PowerShell or JavaScript. Web Browsers: Use browser extensions or settings to block JavaScript execution from untrusted sources.
• Implementation: Configure PowerShell to enforce Constrained Language Mode for non-administrator users. (e.g., Set-ExecutionPolicy AllSigned)

Executable Blocking:

• Use Case: Prevent execution of binaries from suspicious locations, such as %TEMP% or %APPDATA% directories.
• Implementation: Block execution of .exe, .bat, or .ps1 files from user-writable directories.

Dynamic Analysis Prevention:

• Use Case: Use behavior-based execution prevention tools to identify and block malicious activity in real time.
• Implemenation: Employ EDR solutions that analyze runtime behavior and block suspicious code execution.