Прошивка системы
The BIOS (Basic Input/Output System) and The Unified Extensible Firmware Interface (UEFI) or Extensible Firmware Interface (EFI) are examples of system firmware that operate as the software interface between the operating system and hardware of a computer. (Citation: Wikipedia BIOS) (Citation: Wikipedia UEFI) (Citation: About UEFI) System firmware like BIOS and (U)EFI underly the functionality of a computer and may be modified by an adversary to perform or assist in malicious activity. Capabilities exist to overwrite the system firmware, which may give sophisticated adversaries a means to install malicious firmware updates as a means of persistence on a system that may be difficult to detect.
Примеры процедур |
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Название | Описание |
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LoJax |
LoJax is a UEFI BIOS rootkit deployed to persist remote access software on some targeted systems.(Citation: ESET LoJax Sept 2018) |
Hacking Team UEFI Rootkit |
Hacking Team UEFI Rootkit is a UEFI BIOS rootkit developed by the company Hacking Team to persist remote access software on some targeted systems.(Citation: TrendMicro Hacking Team UEFI) |
Trojan.Mebromi |
Trojan.Mebromi performs BIOS modification and can download and execute a file as well as protect itself from removal.(Citation: Ge 2011) |
Контрмеры |
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Контрмера | Описание |
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Update Software |
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. |
Boot Integrity |
Boot Integrity ensures that a system starts securely by verifying the integrity of its boot process, operating system, and associated components. This mitigation focuses on leveraging secure boot mechanisms, hardware-rooted trust, and runtime integrity checks to prevent tampering during the boot sequence. It is designed to thwart adversaries attempting to modify system firmware, bootloaders, or critical OS components. This mitigation can be implemented through the following measures: Implementation of Secure Boot: - Implementation: Enable UEFI Secure Boot on all systems and configure it to allow only signed bootloaders and operating systems. - Use Case: An adversary attempts to replace the system’s bootloader with a malicious version to gain persistence. Secure Boot prevents the untrusted bootloader from executing, halting the attack. Utilization of TPMs: - Implementation: Configure systems to use TPM-based attestation for boot integrity, ensuring that any modification to the firmware, bootloader, or OS is detected. - Use Case: A compromised firmware component alters the boot sequence. The TPM detects the change and triggers an alert, allowing the organization to respond before further damage. Enable Bootloader Passwords: - Implementation: Protect BIOS/UEFI settings with a strong password and limit physical access to devices. - Use Case: An attacker with physical access attempts to disable Secure Boot or modify the boot sequence. The password prevents unauthorized changes. Runtime Integrity Monitoring: - Implementation: Deploy solutions to verify the integrity of critical files and processes after boot. - Use Case: A malware infection modifies kernel modules post-boot. Runtime integrity monitoring detects the modification and prevents the malicious module from loading. |
Privileged Account Management |
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. |
System Firmware Mitigation |
Prevent adversary access to privileged accounts or access necessary to perform this technique. Check the integrity of the existing BIOS or EFI to determine if it is vulnerable to modification. Patch the BIOS and EFI as necessary. Use Trusted Platform Module technology. (Citation: TCG Trusted Platform Module) |
Обнаружение
System firmware manipulation may be detected. (Citation: MITRE Trustworthy Firmware Measurement) Dump and inspect BIOS images on vulnerable systems and compare against known good images. (Citation: MITRE Copernicus) Analyze differences to determine if malicious changes have occurred. Log attempts to read/write to BIOS and compare against known patching behavior. Likewise, EFI modules can be collected and compared against a known-clean list of EFI executable binaries to detect potentially malicious modules. The CHIPSEC framework can be used for analysis to determine if firmware modifications have been performed. (Citation: McAfee CHIPSEC Blog) (Citation: Github CHIPSEC) (Citation: Intel HackingTeam UEFI Rootkit)
Ссылки
- ESET. (2018, September). LOJAX First UEFI rootkit found in the wild, courtesy of the Sednit group. Retrieved July 2, 2019.
- Trusted Computing Group. (2008, April 29). Trusted Platform Module (TPM) Summary. Retrieved June 8, 2016.
- Lin, P. (2015, July 13). Hacking Team Uses UEFI BIOS Rootkit to Keep RCS 9 Agent in Target Systems. Retrieved December 11, 2015.
- Ge, L. (2011, September 9). BIOS Threat is Showing up Again!. Retrieved November 14, 2014.
- Intel Security. (2005, July 16). HackingTeam's UEFI Rootkit Details. Retrieved March 20, 2017.
- Intel. (2017, March 18). CHIPSEC Platform Security Assessment Framework. Retrieved March 20, 2017.
- Beek, C., Samani, R. (2017, March 8). CHIPSEC Support Against Vault 7 Disclosure Scanning. Retrieved March 13, 2017.
- Butterworth, J. (2013, July 30). Copernicus: Question Your Assumptions about BIOS Security. Retrieved December 11, 2015.
- Upham, K. (2014, March). Going Deep into the BIOS with MITRE Firmware Security Research. Retrieved January 5, 2016.
- UEFI Forum. (n.d.). About UEFI Forum. Retrieved January 5, 2016.
- Wikipedia. (2017, July 10). Unified Extensible Firmware Interface. Retrieved July 11, 2017.
- Wikipedia. (n.d.). BIOS. Retrieved January 5, 2016.
Связанные риски
Каталоги
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