Anti virus

Description

ASL has a kernel space anti-virus/anti-malware module. As of version 2.2.6 this module is not activated by default. The basic behaviour when activated is prevent the malware from being read, and send an alert via logs.

Installation

Step 1) ASL kernel 2.6.29 and above required

Step 2) Install kernel modules

 yum install kmod-dazuko

Step 3) Enable setting in /etc/asl/config

 CLAMAV_ENABLED="yes"
 CLAMAV_ENABLE_DAZUKO="yes"
 CLAMAV_TCPADDRESS="127.0.0.1"
 CLAMAV_SCANONACCESS="yes"
 CLAMAV_SCANONOPEN="yes"
 CLAMAV_SCANONCLOSE="yes"
 CLAMAV_SCANONEXEC="yes"
 CLAMAV_CLAMUKO_MAXFILESIZE="10m"

Step 4) Set directories to monitor in /etc/asl/dazuko-include. (Note this file may not exist, this is normal). One line per entry

 /path/to/directory
 /path/to/directory2

We do not recommend you set your entire filesystem to be monitored. This is not necessary on most Linux systems, and in general is pointless for a privileged user like root. We recommend you only configure the system to scan directories non-priviliged users can write, upload and modify code in. For example, these directories are a good starting point for most systems:

 /var/www/
 /home
 /var/tmp
 /tmp

DO NOT INCLUDE SIGNATURE DIRECTORIES such as:

 /var/clamav
 /var/lib/clamav
 /etc/httpd/modsecurity.d/

Your should also not include system directories, such as /proc, /sys and /dev.

Step 5) Optional, set directories to exclude in /etc/asl/dazuko-exclude. (Note this file may not exist, this is normal). One line per entry

 /path/to/directory/exclude1
 /path/to/directory/exclude2

If you are running a control panel, such as Plesk, that puts apache configuration files in /var/www, you have included /var/www in dazukos include paths (a good idea for web servers), and those configuration files and directories can only be modified by root (which is the case with Plesk), then you should exclude those directories. They contains dozens of files each, and failure to exclude them will cause long startup times for Apache as clamd will be forced to scan every configuration file. This is unnecessary and will take several minutes to complete. The directories you should exclude are:

 /var/www/vhosts/www.example.com/statistics/
 /var/www/vhosts/www.example.com/conf/
 /var/www/vhosts/www.example.com/pd/

You can not use wildcards. If you are using a system that puts your virtual hosts in /var/www/vhosts you can use this command to get a list of directories to ignore:

 find /var/www/vhosts/ -type d  | egrep "/(statistics|conf|pd)$"

A future version of ASL will configure this automatically.

Step 6) Update the security policy with:

 asl -s -f

Step 7) Reboot

 reboot