T1698: Indirect Prompt Injection

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.

Network segmentation involves dividing a network into smaller, isolated segments to control and limit the flow of traffic between devices, systems, and applications. By segmenting networks, organizations can reduce the attack surface, restrict lateral movement by adversaries, and protect critical assets from compromise. Effective network segmentation leverages a combination of physical boundaries, logical separation through VLANs, and access control policies enforced by network appliances like firewalls, routers, and cloud-based configurations. This mitigation can be implemented through the following measures: Segment Critical Systems: - Identify and group systems based on their function, sensitivity, and risk. Examples include payment systems, HR databases, production systems, and internet-facing servers. - Use VLANs, firewalls, or routers to enforce logical separation. Implement DMZ for Public-Facing Services: - Host web servers, DNS servers, and email servers in a DMZ to limit their access to internal systems. - Apply strict firewall rules to filter traffic between the DMZ and internal networks. Use Cloud-Based Segmentation: - In cloud environments, use VPCs, subnets, and security groups to isolate applications and enforce traffic rules. - Apply AWS Transit Gateway or Azure VNet peering for controlled connectivity between cloud segments. Apply Microsegmentation for Workloads: - Use software-defined networking (SDN) tools to implement workload-level segmentation and prevent lateral movement. Restrict Traffic with ACLs and Firewalls: - Apply Access Control Lists (ACLs) to network devices to enforce "deny by default" policies. - Use firewalls to restrict both north-south (external-internal) and east-west (internal-internal) traffic. Monitor and Audit Segmented Networks: - Regularly review firewall rules, ACLs, and segmentation policies. - Monitor network flows for anomalies to ensure segmentation is effective. Test Segmentation Effectiveness: - Perform periodic penetration tests to verify that unauthorized access is blocked between network segments.

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.

User Training involves educating employees and contractors on recognizing, reporting, and preventing cyber threats that rely on human interaction, such as phishing, social engineering, and other manipulative techniques. Comprehensive training programs create a human firewall by empowering users to be an active component of the organization's cybersecurity defenses. This mitigation can be implemented through the following measures: Create Comprehensive Training Programs: - Design training modules tailored to the organization's risk profile, covering topics such as phishing, password management, and incident reporting. - Provide role-specific training for high-risk employees, such as helpdesk staff or executives. Use Simulated Exercises: - Conduct phishing simulations to measure user susceptibility and provide targeted follow-up training. - Run social engineering drills to evaluate employee responses and reinforce protocols. Leverage Gamification and Engagement: - Introduce interactive learning methods such as quizzes, gamified challenges, and rewards for successful detection and reporting of threats. Incorporate Security Policies into Onboarding: - Include cybersecurity training as part of the onboarding process for new employees. - Provide easy-to-understand materials outlining acceptable use policies and reporting procedures. Regular Refresher Courses: - Update training materials to include emerging threats and techniques used by adversaries. - Ensure all employees complete periodic refresher courses to stay informed. Emphasize Real-World Scenarios: - Use case studies of recent attacks to demonstrate the consequences of successful phishing or social engineering. - Discuss how specific employee actions can prevent or mitigate such attacks.