Audit

Check for common UAC bypass weaknesses on Windows systems to be aware of the risk posture and address issues where appropriate.^[1]

Routinely check applications using Automation under Security & Privacy System Preferences. To reset permissions, user's can utilize the tccutil reset command. When using Mobile Device Management (MDM), review the list of enabled or disabled applications in the MDMOverrides.plist which overrides the TCC database.^[2]

System scans can be performed to identify unauthorized archival utilities.

Use auditing tools capable of detecting privilege and service abuse opportunities on systems within an enterprise and correct them.

Use auditing tools capable of detecting folder permissions abuse opportunities on systems, especially reviewing changes made to folders by third-party software.

Consider periodic review of accounts and privileges for critical and sensitive Confluence repositories.

Consider periodic review of accounts and privileges for critical and sensitive SharePoint repositories.

Consider periodic reviews of accounts and privileges for critical and sensitive code repositories. Scan code repositories for exposed credentials or other sensitive information.

Identify and correct GPO permissions abuse opportunities (ex: GPO modification privileges) using auditing tools such as BloodHound (version 1.5.1 and later).^[5]

Enterprise email solutions have monitoring mechanisms that may include the ability to audit auto-forwarding rules on a regular basis.

In an Exchange environment, Administrators can use Get-InboxRule / Remove-InboxRule and Get-TransportRule / Remove-TransportRule to discover and remove potentially malicious auto-fowarding and transport rules.^[6][7][8] In addition to this, a MAPI Editor can be utilized to examine the underlying database structure and discover any modifications/tampering of the properties of auto-forwarding rules.^[9]

Administrators should perform an audit of all access lists and the permissions they have been granted to access web applications and services. This should be done extensively on all resources in order to establish a baseline, followed up on with periodic audits of new or updated resources. Suspicious accounts/credentials should be investigated and removed.

Enable advanced auditing on AD FS. Check the success and failure audit options in the AD FS Management snap-in. Enable Audit Application Generated events on the AD FS farm via Group Policy Object.^[10]

Use auditing tools capable of detecting DLL search order hijacking opportunities on systems within an enterprise and correct them. Toolkits like the PowerSploit framework contain PowerUp modules that can be used to explore systems for DLL hijacking weaknesses.^[11]

Use the program sxstrace.exe that is included with Windows along with manual inspection to check manifest files for side-by-side problems in software.^[15]

Use auditing tools capable of detecting file system permissions abuse opportunities on systems within an enterprise and correct them. Toolkits like the PowerSploit framework contain PowerUp modules that can be used to explore systems for service file system permissions weaknesses.^[11]

Find and eliminate path interception weaknesses in program configuration files, scripts, the PATH environment variable, services, and in shortcuts by surrounding PATH variables with quotation marks when functions allow for them. Be aware of the search order Windows uses for executing or loading binaries and use fully qualified paths wherever appropriate.

Clean up old Windows Registry keys when software is uninstalled to avoid keys with no associated legitimate binaries. Periodically search for and correct or report path interception weaknesses on systems that may have been introduced using custom or available tools that report software using insecure path configurations.^[12][13][14]

Find and eliminate path interception weaknesses in program configuration files, scripts, the PATH environment variable, services, and in shortcuts by surrounding PATH variables with quotation marks when functions allow for them. Be aware of the search order Windows uses for executing or loading binaries and use fully qualified paths wherever appropriate.

Clean up old Windows Registry keys when software is uninstalled to avoid keys with no associated legitimate binaries. Periodically search for and correct or report path interception weaknesses on systems that may have been introduced using custom or available tools that report software using insecure path configurations.^[12][13][14]

Find and eliminate path interception weaknesses in program configuration files, scripts, the PATH environment variable, services, and in shortcuts by surrounding PATH variables with quotation marks when functions allow for them. Be aware of the search order Windows uses for executing or loading binaries and use fully qualified paths wherever appropriate.

Clean up old Windows Registry keys when software is uninstalled to avoid keys with no associated legitimate binaries. Periodically search for and correct or report path interception weaknesses on systems that may have been introduced using custom or available tools that report software using insecure path configurations.^[12][13][14]

Use auditing tools capable of detecting file system permissions abuse opportunities on systems within an enterprise and correct them. Toolkits like the PowerSploit framework contain PowerUp modules that can be used to explore systems for service file system permissions weaknesses.^[11]

Consider periodic review of auditpol settings for Administrator accounts and perform dynamic baselining on SIEM(s) to investigate potential malicious activity. Also ensure that the EventLog service and its threads are properly running.

Routinely check account role permissions to ensure only expected users and roles have permission to modify system firewalls.

Routinely check account role permissions to ensure only expected users and roles have permission to modify cloud firewalls.

Routinely check account role permissions to ensure only expected users and roles have permission to modify logging settings.

To ensure Audit rules can not be modified at runtime, add the auditctl -e 2 as the last command in the audit.rules files. Once started, any attempt to change the configuration in this mode will be audited and denied. The configuration can only be changed by rebooting the machine.

Review MFA actions alongside authentication logs to ensure that MFA-based logins are functioning as intended. Review user accounts to ensure that all accounts have MFA enabled.^[18]

Periodically review the hybrid identity solution in use for any discrepancies. For example, review all PTA agents in the Azure Management Portal to identify any unwanted or unapproved ones.^[16] If ADFS is in use, review DLLs and executable files in the AD FS and Global Assembly Cache directories to ensure that they are signed by Microsoft. Note that in some cases binaries may be catalog-signed, which may cause the file to appear unsigned when viewing file properties.^[17]

Periodically review for new and unknown network provider DLLs within the Registry (HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\<NetworkProviderName>\NetworkProvider\ProviderPath).

Ensure only valid network provider DLLs are registered. The name of these can be found in the Registry key at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\NetworkProvider\Order, and have corresponding service subkey pointing to a DLL at HKEY_LOCAL_MACHINE\SYSTEM\CurrentC ontrolSet\Services\<NetworkProviderName>\NetworkProvider.

Routinely check user permissions to ensure only the expected users have the capability to create snapshots and backups.

Routinely check user permissions to ensure only the expected users have the capability to create new instances.

Routinely check user permissions to ensure only the expected users have the capability to delete new instances.

Routinely monitor user permissions to ensure only the expected users have the capability to request quota adjustments or modify tenant-level compute settings.

Consider periodic review of common fileless storage locations (such as the Registry or WMI repository) to potentially identify abnormal and malicious data.

Audit applications and their permissions to ensure access to data and resources are limited based upon necessity and principle of least privilege.

Periodically check the integrity of system image to ensure it has not been modified. ^{[19] [20] [21]}

Periodically check the integrity of the running configuration and system image to ensure they have not been modified. ^{[20] [19] [21]}

Audit the Remote Desktop Users group membership regularly. Remove unnecessary accounts and groups from Remote Desktop Users groups.

Inventory workstations for unauthorized VNC server software.

Toolkits like the PowerSploit framework contain PowerUp modules that can be used to explore systems for permission weaknesses in scheduled tasks that could be used to escalate privileges. ^[11] Windows operating system also creates a registry key specifically associated with the creation of a scheduled task on the destination host at: Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tree\At1. ^[22] In Linux and macOS environments, scheduled tasks using at can be audited locally, or through centrally collected logging, using syslog, or auditd events from the host. ^[23]

Review changes to the cron schedule. cron execution can be reviewed within the /var/log directory. To validate the location of the cron log file, check the syslog config at /etc/rsyslog.conf or /etc/syslog.conf

Toolkits like the PowerSploit framework contain PowerUp modules that can be used to explore systems for permission weaknesses in scheduled tasks that could be used to escalate privileges. ^[11]

Scan public code repositories for exposed credentials or other sensitive information before making commits. Ensure that any leaked credentials are removed from the commit history, not just the current latest version of the code.

Regularly check component software on critical services that adversaries may target for persistence to verify the integrity of the systems and identify if unexpected changes have been made.

Regularly check component software on critical services that adversaries may target for persistence to verify the integrity of the systems and identify if unexpected changes have been made.

Regularly check installed IIS components to verify the integrity of the web server and identify if unexpected changes have been made.

Regularly check component software on critical services that adversaries may target for persistence to verify the integrity of the systems and identify if unexpected changes have been made.

Kerberos preauthentication is enabled by default. Older protocols might not support preauthentication therefore it is possible to have this setting disabled. Make sure that all accounts have preauthentication whenever possible and audit changes to setting. Windows tools such as PowerShell may be used to easily find which accounts have preauthentication disabled. ^[27][28]

Preemptively search for files containing passwords and take actions to reduce the exposure risk when found.

Proactively search for credentials within the Registry and attempt to remediate the risk.

Ensure only authorized keys are allowed access to critical resources and audit access lists regularly.

Search SYSVOL for any existing GGPs that may contain credentials and remove them.^[29]

Preemptively search through communication services to find shared unsecured credentials. Searching for common patterns like "password is ", "password=" and take actions to reduce exposure when found.

Administrators should audit all cloud and container accounts to ensure that they are necessary and that the permissions granted to them are appropriate. Where possible, the ability to request temporary account tokens on behalf of another accounts should be disabled. Additionally, administrators can leverage audit tools to monitor actions that can be conducted as a result of OAuth 2.0 access. For instance, audit reports enable admins to identify privilege escalation actions such as role creations or policy modifications, which could be actions performed after initial access.