T1218: System Binary Proxy Execution

Deploy capabilities that detect, block, and mitigate conditions indicative of software exploits. These capabilities aim to prevent exploitation by addressing vulnerabilities, monitoring anomalous behaviors, and applying exploit-mitigation techniques to harden systems and software.

Operating System Exploit Protections:

- Use Case: Enable built-in exploit protection features provided by modern operating systems, such as Microsoft's Exploit Protection, which includes techniques like Data Execution Prevention (DEP), Address Space Layout Randomization (ASLR), and Control Flow Guard (CFG). - Implementation: Enforce DEP for all programs and enable ASLR to randomize memory addresses used by system and application processes. Windows: Configure Exploit Protection through the Windows Security app or deploy settings via Group Policy. `ExploitProtectionExportSettings.exe -path "exploit_settings.xml"` Linux: Use Kernel-level hardening features like SELinux, AppArmor, or GRSEC to enforce memory protections and prevent exploits.

Third-Party Endpoint Security:

- Use Case: Use endpoint protection tools with built-in exploit protection, such as enhanced memory protection, behavior monitoring, and real-time exploit detection. - Implementation: Deploy tools to detect and block exploitation attempts targeting unpatched software.

Virtual Patching: - Use Case: Use tools to implement virtual patches that mitigate vulnerabilities in applications or operating systems until official patches are applied. - Implementation: Use Intrusion Prevention System (IPS) to block exploitation attempts on known vulnerabilities in outdated applications.

Hardening Application Configurations:

- Use Case: Disable risky application features that can be exploited, such as macros in Microsoft Office or JScript in Internet Explorer. - Implementation: Configure Microsoft Office Group Policies to disable execution of macros in downloaded files.

Employ network appliances and endpoint software to filter ingress, egress, and lateral network traffic. This includes protocol-based filtering, enforcing firewall rules, and blocking or restricting traffic based on predefined conditions to limit adversary movement and data exfiltration. This mitigation can be implemented through the following measures:

Ingress Traffic Filtering:

- Use Case: Configure network firewalls to allow traffic only from authorized IP addresses to public-facing servers. - Implementation: Limit SSH (port 22) and RDP (port 3389) traffic to specific IP ranges.

Egress Traffic Filtering:

- Use Case: Use firewalls or endpoint security software to block unauthorized outbound traffic to prevent data exfiltration and command-and-control (C2) communications. - Implementation: Block outbound traffic to known malicious IPs or regions where communication is unexpected.

Protocol-Based Filtering:

- Use Case: Restrict the use of specific protocols that are commonly abused by adversaries, such as SMB, RPC, or Telnet, based on business needs. - Implementation: Disable SMBv1 on endpoints to prevent exploits like EternalBlue.

Network Segmentation:

- Use Case: Create network segments for critical systems and restrict communication between segments unless explicitly authorized. - Implementation: Implement VLANs to isolate IoT devices or guest networks from core business systems.

Application Layer Filtering:

- Use Case: Use proxy servers or Web Application Firewalls (WAFs) to inspect and block malicious HTTP/S traffic. - Implementation: Configure a WAF to block SQL injection attempts or other web application exploitation techniques.

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.

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.

Disable or remove unnecessary and potentially vulnerable software, features, or services to reduce the attack surface and prevent abuse by adversaries. This involves identifying software or features that are no longer needed or that could be exploited and ensuring they are either removed or properly disabled. This mitigation can be implemented through the following measures:

Remove Legacy Software:

- Use Case: Disable or remove older versions of software that no longer receive updates or security patches (e.g., legacy Java, Adobe Flash). - Implementation: A company removes Flash Player from all employee systems after it has reached its end-of-life date.

Disable Unused Features:

- Use Case: Turn off unnecessary operating system features like SMBv1, Telnet, or RDP if they are not required. - Implementation: Disable SMBv1 in a Windows environment to mitigate vulnerabilities like EternalBlue.

Control Applications Installed by Users:

- Use Case: Prevent users from installing unauthorized software via group policies or other management tools. - Implementation: Block user installations of unauthorized file-sharing applications (e.g., BitTorrent clients) in an enterprise environment.

Remove Unnecessary Services:

- Use Case: Identify and disable unnecessary default services running on endpoints, servers, or network devices. - Implementation: Disable unused administrative shares (e.g., C$, ADMIN$) on workstations.

Restrict Add-ons and Plugins:

- Use Case: Remove or disable browser plugins and add-ons that are not needed for business purposes. - Implementation: Disable Java and ActiveX plugins in web browsers to prevent drive-by attacks.

Restricting web-based content involves enforcing policies and technologies that limit access to potentially malicious websites, unsafe downloads, and unauthorized browser behaviors. This can include URL filtering, download restrictions, script blocking, and extension control to protect against exploitation, phishing, and malware delivery. This mitigation can be implemented through the following measures:

Deploy Web Proxy Filtering:

- Use solutions to filter web traffic based on categories, reputation, and content types. - Enforce policies that block unsafe websites or file types at the gateway level.

Enable DNS-Based Filtering:

- Implement tools to restrict access to domains associated with malware or phishing campaigns. - Use public DNS filtering services to enhance protection.

Enforce Content Security Policies (CSP):

- Configure CSP headers on internal and external web applications to restrict script execution, iframe embedding, and cross-origin requests.

Control Browser Features:

- Disable unapproved browser features like automatic downloads, developer tools, or unsafe scripting. - Enforce policies through tools like Group Policy Management to control browser settings.

Monitor and Alert on Web-Based Threats:

- Use SIEM tools to collect and analyze web proxy logs for signs of anomalous or malicious activity. - Configure alerts for access attempts to blocked domains or repeated file download failures.