Detect USB Storage

Windows endpoint

On the Windows endpoint, we want to monitor the output of the USBSTOR registry entry using the reg Query command. Then, we create a rule to trigger an alert when the command output contains a value.

Perform the following steps on the Windows endpoint.

1. Enable remote command execution on the Windows endpoint by appending the following settings to the C:\Program Files (x86)\ossec-agent\local_internal_options.conf file:

   Warning

   Enable remote command execution with caution as this gives the Wazuh user permission to run any command on the endpoint.

   logcollector.remote_commands=1
   

2. Restart the Wazuh agent to apply the changes, using PowerShell with administrator privileges:

   > Restart-Service -Name wazuh
   

Wazuh server

Perform the following steps on the Wazuh server.

1. Append the following configuration to the /var/ossec/etc/shared/default/agent.conf file on the Wazuh server:

   <agent_config os="Windows">
     <localfile>
       <log_format>command</log_format>
       <command>reg QUERY HKLM\SYSTEM\CurrentControlSet\Enum\USBSTOR</command>
       <alias>check_usb_connetivity</alias>
     </localfile>
   </agent_config>
   

   Where:

   • The value command of the <log_format> tag specifies the output of the command is read as multiple events.

   • The value reg QUERY HKLM\SYSTEM\CurrentControlSet\Enum\USBSTOR of the <command> tag is the command the Logcollector module executes to know if a USB device is attached to the endpoint.

   • The value check_usb_connetivity of the <alias> tag is a string that represents the reg QUERY HKLM\SYSTEM\CurrentControlSet\Enum\USBSTOR command for better identification in creating rules.

2. Add the following rules to the /var/ossec/etc/rules/local_rules.xml file on the Wazuh server:

   <group name="detect_usb_storage,">
     <rule id="100016" level="7">
       <if_sid>530</if_sid>
       <match>^ossec: output: 'check_usb_connetivity':</match>
       <description>New USB device connected</description>
     </rule>
   </group>
   

3. Restart the Wazuh manager to apply the changes:

   $ sudo systemctl restart wazuh-manager