Level 2 - Server Level 2 - Workstation
Monitor the loading and unloading of kernel modules. The programs insmod (install a kernel module), rmmod (remove a kernel module), and modprobe (a more sophisticated program to load and unload modules, as well as some other features) control loading and unloading of modules. The init_module (load a module) and delete_module (delete a module) system calls control loading and unloading of modules. Any execution of the loading and unloading module programs and system calls will trigger an audit record with an identifier of “modules”.
Monitoring the use of insmod, rmmod and modprobe could provide system administrators with evidence that an unauthorized user loaded or unloaded a kernel module, possibly compromising the security of the system. Monitoring of the init_module and delete_module system calls would reflect an unauthorized user attempting to use a different program to load and unload modules.
On a 32 bit system run the following command and verify the output matches:
# grep modules /etc/audit/audit.rules -w /sbin/insmod -p x -k modules -w /sbin/rmmod -p x -k modules -w /sbin/modprobe -p x -k modules -a always,exit arch=b32 -S init_module -S delete_module -k modules
On a 64 bit system run the following command and verify the output matches:
# grep modules /etc/audit/audit.rules -w /sbin/insmod -p x -k modules -w /sbin/rmmod -p x -k modules -w /sbin/modprobe -p x -k modules -a always,exit arch=b64 -S init_module -S delete_module -k modules
For 32 bit systems add the following lines to the /etc/audit/audit.rules file:
-w /sbin/insmod -p x -k modules -w /sbin/rmmod -p x -k modules -w /sbin/modprobe -p x -k modules -a always,exit arch=b32 -S init_module -S delete_module -k modules
For 64 bit systems add the following lines to the /etc/audit/audit.rules file:
-w /sbin/insmod -p x -k modules -w /sbin/rmmod -p x -k modules -w /sbin/modprobe -p x -k modules -a always,exit arch=b64 -S init_module -S delete_module -k modules