LSASS Driver

Restricting library loading involves implementing security controls to ensure that only trusted and verified libraries (DLLs, shared objects, etc.) are loaded into processes. Adversaries often abuse Dynamic-Link Library (DLL) Injection, DLL Search Order Hijacking, or LD_PRELOAD mechanisms to execute malicious code by forcing the operating system to load untrusted libraries. This mitigation can be implemented through the following measures: Enforce Safe Library Loading Practices: - Enable `SafeDLLSearchMode` on Windows. - Restrict `LD_PRELOAD` and `LD_LIBRARY_PATH` usage on Linux systems. Code Signing Enforcement: - Require digital signatures for all libraries loaded into processes. - Use tools like Signtool, and WDAC to enforce signed DLL execution. Environment Hardening: - Secure library paths and directories to prevent adversaries from placing rogue libraries. - Monitor user-writable directories and system configurations for unauthorized changes. Audit and Monitor Library Loading: - Enable `Sysmon` on Windows to monitor for suspicious library loads. - Use `auditd` on Linux to monitor shared library paths and configuration file changes. Use Application Control Solutions: - Implement AppLocker, WDAC, or SELinux to allow only trusted libraries. *Tools for Implementation* Windows-Specific Tools: - AppLocker: Application whitelisting for DLLs. - Windows Defender Application Control (WDAC): Restrict unauthorized library execution. - Signtool: Verify and enforce code signing. - Sysmon: Monitor DLL load events (Event ID 7). Linux-Specific Tools: - auditd: Monitor changes to library paths and critical files. - SELinux/AppArmor: Define policies to restrict library loading. - ldconfig and chattr: Secure LD configuration files and prevent unauthorized modifications. Cross-Platform Solutions: - Wazuh or OSSEC: File integrity monitoring for library changes. - Tripwire: Detect and alert on unauthorized library modifications.

Credential Access Protection focuses on implementing measures to prevent adversaries from obtaining credentials, such as passwords, hashes, tokens, or keys, that could be used for unauthorized access. This involves restricting access to credential storage mechanisms, hardening configurations to block credential dumping methods, and using monitoring tools to detect suspicious credential-related activity. This mitigation can be implemented through the following measures: Restrict Access to Credential Storage: - Use Case: Prevent adversaries from accessing the SAM (Security Account Manager) database on Windows systems. - Implementation: Enforce least privilege principles and restrict administrative access to credential stores such as `C:\Windows\System32\config\SAM`. Use Credential Guard: - Use Case: Isolate LSASS (Local Security Authority Subsystem Service) memory to prevent credential dumping. - Implementation: Enable Windows Defender Credential Guard on enterprise endpoints to isolate secrets and protect them from unauthorized access. Monitor for Credential Dumping Tools: - Use Case: Detect and block known tools like Mimikatz or Windows Credential Editor. - Implementation: Flag suspicious process behavior related to credential dumping. Disable Cached Credentials: - Use Case: Prevent adversaries from exploiting cached credentials on endpoints. - Implementation: Configure group policy to reduce or eliminate the use of cached credentials (e.g., set Interactive logon: Number of previous logons to cache to 0). Enable Secure Boot and Memory Protections: - Use Case: Prevent memory-based attacks used to extract credentials. - Implementation: Configure Secure Boot and enforce hardware-based security features like DEP (Data Execution Prevention) and ASLR (Address Space Layout Randomization).

On Windows 8.1 and Server 2012 R2, enable LSA Protection by setting the Registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\RunAsPPL to dword:00000001. (Citation: Microsoft LSA Protection Mar 2014) LSA Protection ensures that LSA plug-ins and drivers are only loaded if they are digitally signed with a Microsoft signature and adhere to the Microsoft Security Development Lifecycle (SDL) process guidance. On Windows 10 and Server 2016, enable Windows Defender Credential Guard (Citation: Microsoft Enable Cred Guard April 2017) to run lsass.exe in an isolated virtualized environment without any device drivers. (Citation: Microsoft Credential Guard April 2017) Ensure safe DLL search mode is enabled HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\SafeDllSearchMode to mitigate risk that lsass.exe loads a malicious code library. (Citation: Microsoft DLL Security)

Code Signing is a security process that ensures the authenticity and integrity of software by digitally signing executables, scripts, and other code artifacts. It prevents untrusted or malicious code from executing by verifying the digital signatures against trusted sources. Code signing protects against tampering, impersonation, and distribution of unauthorized or malicious software, forming a critical defense against supply chain and software exploitation attacks. This mitigation can be implemented through the following measures: Enforce Signed Code Execution: - Implementation: Configure operating systems (e.g., Windows with AppLocker or Linux with Secure Boot) to allow only signed code to execute. - Use Case: Prevent the execution of malicious PowerShell scripts by requiring all scripts to be signed with a trusted certificate. Vendor-Signed Driver Enforcement: - Implementation: Enable kernel-mode code signing to ensure that only drivers signed by trusted vendors can be loaded. - Use Case: A malicious driver attempting to modify system memory fails to load because it lacks a valid signature. Certificate Revocation Management: - Implementation: Use Online Certificate Status Protocol (OCSP) or Certificate Revocation Lists (CRLs) to block certificates associated with compromised or deprecated code. - Use Case: A compromised certificate used to sign a malicious update is revoked, preventing further execution of the software. Third-Party Software Verification: - Implementation: Require software from external vendors to be signed with valid certificates before deployment. - Use Case: An organization only deploys signed and verified third-party software to prevent supply chain attacks. Script Integrity in CI/CD Pipelines: - Implementation: Integrate code signing into CI/CD pipelines to sign and verify code artifacts before production release. - Use Case: A software company ensures that all production builds are signed, preventing tampered builds from reaching customers. **Key Components of Code Signing** - Digital Signature Verification: Verifies the authenticity of code by ensuring it was signed by a trusted entity. - Certificate Management: Uses Public Key Infrastructure (PKI) to manage signing certificates and revocation lists. - Enforced Policy for Unsigned Code: Prevents the execution of unsigned or untrusted binaries and scripts. - Hash Integrity Check: Confirms that code has not been altered since signing by comparing cryptographic hashes.