T1574: Hijack Execution Flow

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.

Behavior Prevention on Endpoint refers to the use of technologies and strategies to detect and block potentially malicious activities by analyzing the behavior of processes, files, API calls, and other endpoint events. Rather than relying solely on known signatures, this approach leverages heuristics, machine learning, and real-time monitoring to identify anomalous patterns indicative of an attack. This mitigation can be implemented through the following measures:

Suspicious Process Behavior:

- Implementation: Use Endpoint Detection and Response (EDR) tools to monitor and block processes exhibiting unusual behavior, such as privilege escalation attempts. - Use Case: An attacker uses a known vulnerability to spawn a privileged process from a user-level application. The endpoint tool detects the abnormal parent-child process relationship and blocks the action.

Unauthorized File Access:

- Implementation: Leverage Data Loss Prevention (DLP) or endpoint tools to block processes attempting to access sensitive files without proper authorization. - Use Case: A process tries to read or modify a sensitive file located in a restricted directory, such as /etc/shadow on Linux or the SAM registry hive on Windows. The endpoint tool identifies this anomalous behavior and prevents it.

Abnormal API Calls:

- Implementation: Implement runtime analysis tools to monitor API calls and block those associated with malicious activities. - Use Case: A process dynamically injects itself into another process to hijack its execution. The endpoint detects the abnormal use of APIs like `OpenProcess` and `WriteProcessMemory` and terminates the offending process.

Exploit Prevention:

- Implementation: Use behavioral exploit prevention tools to detect and block exploits attempting to gain unauthorized access. - Use Case: A buffer overflow exploit is launched against a vulnerable application. The endpoint detects the anomalous memory write operation and halts the process.

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.

Auditing is the process of recording activity and systematically reviewing and analyzing the activity and system configurations. The primary purpose of auditing is to detect anomalies and identify potential threats or weaknesses in the environment. Proper auditing configurations can also help to meet compliance requirements. The process of auditing encompasses regular analysis of user behaviors and system logs in support of proactive security measures.

Auditing is applicable to all systems used within an organization, from the front door of a building to accessing a file on a fileserver. It is considered more critical for regulated industries such as, healthcare, finance and government where compliance requirements demand stringent tracking of user and system activates.This mitigation can be implemented through the following measures:

System Audit:

- Use Case: Regularly assess system configurations to ensure compliance with organizational security policies. - Implementation: Use tools to scan for deviations from established benchmarks.

Permission Audits:

- Use Case: Review file and folder permissions to minimize the risk of unauthorized access or privilege escalation. - Implementation: Run access reviews to identify users or groups with excessive permissions.

Software Audits:

- Use Case: Identify outdated, unsupported, or insecure software that could serve as an attack vector. - Implementation: Use inventory and vulnerability scanning tools to detect outdated versions and recommend secure alternatives.

Configuration Audits:

- Use Case: Evaluate system and network configurations to ensure secure settings (e.g., disabled SMBv1, enabled MFA). - Implementation: Implement automated configuration scanning tools like SCAP (Security Content Automation Protocol) to identify non-compliant systems.

Network Audits:

- Use Case: Examine network traffic, firewall rules, and endpoint communications to identify unauthorized or insecure connections. - Implementation: Utilize tools such as Wireshark, or Zeek to monitor and log suspicious network behavior.

Application Developer Guidance focuses on providing developers with the knowledge, tools, and best practices needed to write secure code, reduce vulnerabilities, and implement secure design principles. By integrating security throughout the software development lifecycle (SDLC), this mitigation aims to prevent the introduction of exploitable weaknesses in applications, systems, and APIs. This mitigation can be implemented through the following measures: Preventing SQL Injection (Secure Coding Practice):

- Implementation: Train developers to use parameterized queries or prepared statements instead of directly embedding user input into SQL queries. - Use Case: A web application accepts user input to search a database. By sanitizing and validating user inputs, developers can prevent attackers from injecting malicious SQL commands.

Cross-Site Scripting (XSS) Mitigation:

- Implementation: Require developers to implement output encoding for all user-generated content displayed on a web page. - Use Case: An e-commerce site allows users to leave product reviews. Properly encoding and escaping user inputs prevents malicious scripts from being executed in other users’ browsers.

Secure API Design:

- Implementation: Train developers to authenticate all API endpoints and avoid exposing sensitive information in API responses. - Use Case: A mobile banking application uses APIs for account management. By enforcing token-based authentication for every API call, developers reduce the risk of unauthorized access.

Static Code Analysis in the Build Pipeline:

- Implementation: Incorporate tools into CI/CD pipelines to automatically scan for vulnerabilities during the build process. - Use Case: A fintech company integrates static analysis tools to detect hardcoded credentials in their source code before deployment.

Threat Modeling in the Design Phase:

- Implementation: Use frameworks like STRIDE (Spoofing, Tampering, Repudiation, Information Disclosure, Denial of Service, Elevation of Privilege) to assess threats during application design. - Use Case: Before launching a customer portal, a SaaS company identifies potential abuse cases, such as session hijacking, and designs mitigations like secure session management.

**Tools for Implementation**:

- Static Code Analysis Tools: Use tools that can scan for known vulnerabilities in source code. - Dynamic Application Security Testing (DAST): Use tools like Burp Suite or OWASP ZAP to simulate runtime attacks and identify vulnerabilities. - Secure Frameworks: Recommend secure-by-default frameworks (e.g., Django for Python, Spring Security for Java) that enforce security best practices.

User Account Management involves implementing and enforcing policies for the lifecycle of user accounts, including creation, modification, and deactivation. Proper account management reduces the attack surface by limiting unauthorized access, managing account privileges, and ensuring accounts are used according to organizational policies. This mitigation can be implemented through the following measures:

Enforcing the Principle of Least Privilege

- Implementation: Assign users only the minimum permissions required to perform their job functions. Regularly audit accounts to ensure no excess permissions are granted. - Use Case: Reduces the risk of privilege escalation by ensuring accounts cannot perform unauthorized actions.

Implementing Strong Password Policies

- Implementation: Enforce password complexity requirements (e.g., length, character types). Require password expiration every 90 days and disallow password reuse. - Use Case: Prevents adversaries from gaining unauthorized access through password guessing or brute force attacks.

Managing Dormant and Orphaned Accounts

- Implementation: Implement automated workflows to disable accounts after a set period of inactivity (e.g., 30 days). Remove orphaned accounts (e.g., accounts without an assigned owner) during regular account audits. - Use Case: Eliminates dormant accounts that could be exploited by attackers.

Account Lockout Policies

- Implementation: Configure account lockout thresholds (e.g., lock accounts after five failed login attempts). Set lockout durations to a minimum of 15 minutes. - Use Case: Mitigates automated attack techniques that rely on repeated login attempts.

Multi-Factor Authentication (MFA) for High-Risk Accounts

- Implementation: Require MFA for all administrative accounts and high-risk users. Use MFA mechanisms like hardware tokens, authenticator apps, or biometrics. - Use Case: Prevents unauthorized access, even if credentials are stolen.

Restricting Interactive Logins

- Implementation: Restrict interactive logins for privileged accounts to specific secure systems or management consoles. Use group policies to enforce logon restrictions. - Use Case: Protects sensitive accounts from misuse or exploitation.

*Tools for Implementation*

Built-in Tools:

- Microsoft Active Directory (AD): Centralized account management and RBAC enforcement. - Group Policy Object (GPO): Enforce password policies, logon restrictions, and account lockout policies.

Identity and Access Management (IAM) Tools:

- Okta: Centralized user provisioning, MFA, and SSO integration. - Microsoft Azure Active Directory: Provides advanced account lifecycle management, role-based access, and conditional access policies.

Privileged Account Management (PAM): - CyberArk, BeyondTrust, Thycotic: Manage and monitor privileged account usage, enforce session recording, and JIT access.

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.

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.