Firmware Corruption
Adversaries may overwrite or corrupt the flash memory contents of system BIOS or other firmware in devices attached to a system in order to render them inoperable or unable to boot, thus denying the availability to use the devices and/or the system.(Citation: Symantec Chernobyl W95.CIH) Firmware is software that is loaded and executed from non-volatile memory on hardware devices in order to initialize and manage device functionality. These devices may include the motherboard, hard drive, or video cards. In general, adversaries may manipulate, overwrite, or corrupt firmware in order to deny the use of the system or devices. For example, corruption of firmware responsible for loading the operating system for network devices may render the network devices inoperable.(Citation: dhs_threat_to_net_devices)(Citation: cisa_malware_orgs_ukraine) Depending on the device, this attack may also result in Data Destruction.
Procedure Examples |
|
Name | Description |
---|---|
Bad Rabbit |
Bad Rabbit has used an executable that installs a modified bootloader to prevent normal boot-up.(Citation: Secure List Bad Rabbit) |
TrickBot |
TrickBot module "Trickboot" can write or erase the UEFI/BIOS firmware of a compromised device.(Citation: Eclypsium Trickboot December 2020) |
Mitigations |
|
Mitigation | Description |
---|---|
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. |
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. |
Firmware Corruption Mitigation |
Prevent adversary access to privileged accounts or access necessary to perform this technique. Check the integrity of the existing BIOS and device firmware to determine if it is vulnerable to modification. Patch the BIOS and other firmware as necessary to prevent successful use of known vulnerabilities. |
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. |
Detection
System firmware manipulation may be detected.(Citation: MITRE Trustworthy Firmware Measurement) Log attempts to read/write to BIOS and compare against known patching behavior.
References
- Yamamura, M. (2002, April 25). W95.CIH. Retrieved April 12, 2019.
- Upham, K. (2014, March). Going Deep into the BIOS with MITRE Firmware Security Research. Retrieved January 5, 2016.
- U.S. Department of Homeland Security. (2016, August 30). The Increasing Threat to Network Infrastructure Devices and Recommended Mitigations. Retrieved July 29, 2022.
- CISA. (2022, April 28). Alert (AA22-057A) Update: Destructive Malware Targeting Organizations in Ukraine. Retrieved July 29, 2022.
- Mamedov, O. Sinitsyn, F. Ivanov, A.. (2017, October 24). Bad Rabbit ransomware. Retrieved January 28, 2021.
- Eclypsium, Advanced Intelligence. (2020, December 1). TRICKBOT NOW OFFERS ‘TRICKBOOT’: PERSIST, BRICK, PROFIT. Retrieved March 15, 2021.
Связанные риски
Риск | Связи | |
---|---|---|
Закрепление злоумышленника в ОС
из-за
возможности модификации BIOS/UEFI
в микропрограммном обеспечении
Повышение привилегий
НСД
|
|
|
Обход систем защиты
из-за
возможности модификации BIOS/UEFI
в микропрограммном обеспечении
Повышение привилегий
Целостность
|
|
|
Физическое повреждение оборудования
из-за
возможности модификации BIOS/UEFI
в микропрограммном обеспечении
Доступность
Отказ в обслуживании
|
|
|
Неработоспособность операционной системы
из-за
возможности модификации BIOS/UEFI
в микропрограммном обеспечении
Доступность
Отказ в обслуживании
|
|
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