T1543: Create or Modify System Process

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.

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.

Prevent users or groups from installing unauthorized or unapproved software to reduce the risk of introducing malicious or vulnerable applications. This can be achieved through allowlists, software restriction policies, endpoint management tools, and least privilege access principles. This mitigation can be implemented through the following measures:

Application Whitelisting

- Implement Microsoft AppLocker or Windows Defender Application Control (WDAC) to create and enforce allowlists for approved software. - Whitelist applications based on file hash, path, or digital signatures.

Restrict User Permissions

- Remove local administrator rights for all non-IT users. - Use Role-Based Access Control (RBAC) to restrict installation permissions to privileged accounts only.

Software Restriction Policies (SRP)

- Use GPO to configure SRP to deny execution of binaries from directories such as `%AppData%`, `%Temp%`, and external drives. - Restrict specific file types (`.exe`, `.bat`, `.msi`, `.js`, `.vbs`) to trusted directories only.

Endpoint Management Solutions

- Deploy tools like Microsoft Intune, SCCM, or Jamf for centralized software management. - Maintain a list of approved software, versions, and updates across the enterprise.

Monitor Software Installation Events

- Enable logging of software installation events and monitor Windows Event ID 4688 and Event ID 11707 for software installs. - Use SIEM or EDR tools to alert on attempts to install unapproved software.

Implement Software Inventory Management

- Use tools like OSQuery or Wazuh to scan for unauthorized software on endpoints and servers. - Conduct regular audits to detect and remove unapproved software.

*Tools for Implementation*

Application Whitelisting:

- Microsoft AppLocker - Windows Defender Application Control (WDAC)

Endpoint Management:

- Microsoft Intune - SCCM (System Center Configuration Manager) - Jamf Pro (macOS) - Puppet or Ansible for automation

Software Restriction Policies:

- Group Policy Object (GPO) - Microsoft Software Restriction Policies (SRP)

Monitoring and Logging:

- Splunk - OSQuery - Wazuh (open-source SIEM and XDR) - EDRs

Inventory Management and Auditing:

- OSQuery - Wazuh

Privileged Account Management focuses on implementing policies, controls, and tools to securely manage privileged accounts (e.g., SYSTEM, root, or administrative accounts). This includes restricting access, limiting the scope of permissions, monitoring privileged account usage, and ensuring accountability through logging and auditing.This mitigation can be implemented through the following measures:

Account Permissions and Roles:

- Implement RBAC and least privilege principles to allocate permissions securely. - Use tools like Active Directory Group Policies to enforce access restrictions.

Credential Security:

- Deploy password vaulting tools like CyberArk, HashiCorp Vault, or KeePass for secure storage and rotation of credentials. - Enforce password policies for complexity, uniqueness, and expiration using tools like Microsoft Group Policy Objects (GPO).

Multi-Factor Authentication (MFA):

- Enforce MFA for all privileged accounts using Duo Security, Okta, or Microsoft Azure AD MFA.

Privileged Access Management (PAM):

- Use PAM solutions like CyberArk, BeyondTrust, or Thycotic to manage, monitor, and audit privileged access.

Auditing and Monitoring:

- Integrate activity monitoring into your SIEM (e.g., Splunk or QRadar) to detect and alert on anomalous privileged account usage.

Just-In-Time Access:

- Deploy JIT solutions like Azure Privileged Identity Management (PIM) or configure ephemeral roles in AWS and GCP to grant time-limited elevated permissions.

*Tools for Implementation*

Privileged Access Management (PAM):

- CyberArk, BeyondTrust, Thycotic, HashiCorp Vault.

Credential Management:

- Microsoft LAPS (Local Admin Password Solution), Password Safe, HashiCorp Vault, KeePass.

Multi-Factor Authentication:

- Duo Security, Okta, Microsoft Azure MFA, Google Authenticator.

Linux Privilege Management:

- sudo configuration, SELinux, AppArmor.

Just-In-Time Access:

- Azure Privileged Identity Management (PIM), AWS IAM Roles with session constraints, GCP Identity-Aware Proxy.

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.

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.

Software configuration refers to making security-focused adjustments to the settings of applications, middleware, databases, or other software to mitigate potential threats. These changes help reduce the attack surface, enforce best practices, and protect sensitive data. This mitigation can be implemented through the following measures:

Conduct a Security Review of Application Settings:

- Review the software documentation to identify recommended security configurations. - Compare default settings against organizational policies and compliance requirements.

Implement Access Controls and Permissions:

- Restrict access to sensitive features or data within the software. - Enforce least privilege principles for all roles and accounts interacting with the software.

Enable Logging and Monitoring:

- Configure detailed logging for key application events such as authentication failures, configuration changes, or unusual activity. - Integrate logs with a centralized monitoring solution, such as a SIEM.

Update and Patch Software Regularly:

- Ensure the software is kept up-to-date with the latest security patches to address known vulnerabilities. - Use automated patch management tools to streamline the update process.

Disable Unnecessary Features or Services:

- Turn off unused functionality or components that could introduce vulnerabilities, such as debugging interfaces or deprecated APIs.

Test Configuration Changes:

- Perform configuration changes in a staging environment before applying them in production. - Conduct regular audits to ensure that settings remain aligned with security policies.

*Tools for Implementation*

Configuration Management Tools:

- Ansible: Automates configuration changes across multiple applications and environments. - Chef: Ensures consistent application settings through code-based configuration management. - Puppet: Automates software configurations and audits changes for compliance.

Security Benchmarking Tools:

- CIS-CAT: Provides benchmarks and audits for secure software configurations. - Aqua Security Trivy: Scans containerized applications for configuration issues.

Vulnerability Management Solutions:

- Nessus: Identifies misconfigurations and suggests corrective actions.

Logging and Monitoring Tools:

- Splunk: Aggregates and analyzes application logs to detect suspicious activity.

Restricting file and directory permissions involves setting access controls at the file system level to limit which users, groups, or processes can read, write, or execute files. By configuring permissions appropriately, organizations can reduce the attack surface for adversaries seeking to access sensitive data, plant malicious code, or tamper with system files.

Enforce Least Privilege Permissions:

- Remove unnecessary write permissions on sensitive files and directories. - Use file ownership and groups to control access for specific roles.

Example (Windows): Right-click the shared folder → Properties → Security tab → Adjust permissions for NTFS ACLs.

Harden File Shares:

- Disable anonymous access to shared folders. - Enforce NTFS permissions for shared folders on Windows.

Example: Set permissions to restrict write access to critical files, such as system executables (e.g., `/bin` or `/sbin` on Linux). Use tools like `chown` and `chmod` to assign file ownership and limit access.

On Linux, apply: `chmod 750 /etc/sensitive.conf` `chown root:admin /etc/sensitive.conf`

File Integrity Monitoring (FIM):

- Use tools like Tripwire, Wazuh, or OSSEC to monitor changes to critical file permissions.

Audit File System Access:

- Enable auditing to track permission changes or unauthorized access attempts. - Use auditd (Linux) or Event Viewer (Windows) to log activities.

Restrict Startup Directories:

- Configure permissions to prevent unauthorized writes to directories like `C:\ProgramData\Microsoft\Windows\Start Menu`.

Example: Restrict write access to critical directories like `/etc/`, `/usr/local/`, and Windows directories such as `C:\Windows\System32`.

- On Windows, use icacls to modify permissions: `icacls "C:\Windows\System32" /inheritance:r /grant:r SYSTEM:(OI)(CI)F` - On Linux, monitor permissions using tools like `lsattr` or `auditd`.