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ClamAV ansible role

Installs ClamAV on RedHat/CentOS and Debian/Ubuntu Linux servers :

  • On Access scan and access prevention can be activated
  • Periodic scan can be activated (clamscan or faster clamdscan when clamd daemon runs as the root user)
  • Customizable script when detecting virus : only for periodic or manual scans (not for On Access scan) see https://bbs.archlinux.org/viewtopic.php?id=237489 and ClamAV source code to check status on this
  • Freshclam can use an authenticated proxy to update virus databases

Lots of templates and variables but feel free to add/request some more if needed

Requirements

EPEL repositories muse be enabled on RHEL/CentOS (not adding dependency because you may already have something to enable EPEL)

Role Variables

Available variables are listed below, see default values in defaults/main.yml: You can override them in host/group files See OS-specific variable files in var/

  • Freschlam database update

    • Configure optional freshclam http proxy settings using freshclam_proxy.XXXX variables : (each one is optional) :

        freshclam_proxy:
    hostname: "proxy.mydomain.org"
    port: "8080"
    username: "interneuser"
    password: "internetP4ssW0rD"

  • ClamAV daemon service status : started or not and/or enabled or not :

    • clamav_daemon_state: started
    • clamav_daemon_enabled: true

  • ClamAV daemon temporary directory (must not be included as "On Access", see https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=904111
    This role will check and prevent that
    clamav_daemon_temporary_directory: "/var/tmp"

  • ClamAV clamdscan max sizes : (optional) (note : on access scanning has its own values) note : not overwriting ClamAV default values in this role

    • clamav_daemon_max_scan_size: "100M" (default ClamAV value)
    • clamav_daemon_max_file_size: "25M" (default ClamAV value)

  • ClamAV freshclam service status

    • clamav_freshclam_daemon_state: started
    • clamav_freshclam_daemon_enabled: true

  • ClamAV freshclam configuration file

    • clamav_freshclam_daemon_config_path: /etc/freshclam.conf

  • If you do want to change default permissions on ClamAV daemon socket to switch the allowed group to use it Beware that any user user within this group can talk to the clamav daemon, even to shut it down -> DoS

    • clamav_daemon_socket_group: virusgroup

  • What to do when a virus if found :

    • command to launch when virus is found :
      clamav_daemon_virus_event_command : 'echo $(date) - ${CLAM_VIRUSEVENT_VIRUSNAME}: ${CLAM_VIRUSEVENT_FILENAME} | wall'

    • OR External script to launch when virus is found :

      • use external script instead of inline command :
        clamav_daemon_virus_event_use_script: true
        *this script deployed from template clamav_virus_alert.sh.j2 to $*clamav_daemon_virus_event_script_name if $clamav_daemon_virus_event_ansible_deploy_script is true

      • default name of the external script :
        clamav_daemon_virus_event_script_name: "/usr/local/sbin/clamav_virus_alert.sh"

  • On Access scan features : (defining clamav_onaccess_include_paths or clamav_onaccess_mount_paths wil enable On Access scanning, and thus clamd will run as the root user)

    • Paths to be included to On Access scan :
      clamav_onaccess_include_paths (include path list)

    • Mount paths to be included to On Access scan :
      clamav_onaccess_mount_paths (mount path list)

    • Paths to be excluded from On Access scan
      clamav_onaccess_exclude_paths (exclude path list)

    note : OnAccessIncludePath option will be ignored if OnAccessMountPath is enabled (extract from clamd documentation)

  • infected files access prevention : user will get a permission denied when trying to access infected file clamav_daemon_access_prevention: no

  • Periodic scan features :

    • Enable or not periodic scan
      clamav_periodic_scan_enabled: true

    • Periodicity of this periodic scan : choose from "hourly", "daily", "weekly" or "monthly"
      clamav_periodic_scan_periodicity: "weekly"

    • Which script to launch ? :
      clamav_periodic_scan_script: "/usr/local/sbin/clamav_periodic_scan.sh"

    • Periodic scan logfile :
      clamav_periodic_scan_logfile: "/var/log/clamav_periodic_scan.log"

    • Name of the logrotate donfigfile for the above logfile :
      clamav_periodic_scan_logrotate_file: "/etc/logrotate.d/clamav-periodic-scan"

    • Directories to exclude from periodic scan (clamscan): (default values) :
      clamav_periodic_scan_exclusions:

        clamav_periodic_scan_exclusions:
    - /dev
    - /proc
    - /run
    - /sys

    • Same thing in regexp format for clamd configuration (and periodic clamdscan): (default values) clamav_daemon_scan_exclusion_regexps:

        clamav_periodic_scan_exclusion_regexps:
    - "^/dev/"  
    - "^/proc/"  
    - "^/run/"  
    - "^/sys/"  
    - "^/var/lib/sss/pipes/"  
    - "^{{ clamav_daemon_temporary_directory }}/"  
    # access denied on /var/log/audit/audit.log* anyway :p (and the following files/drectories) :  
    - "^/var/log/audit/"  
    - "^/etc/audit/"  
    - "^/etc/selinux/"  
    - "^/etc/(g)?shadow(-)?$"  
    - "^/etc/krb5.keytab$"  
    - "^/etc/security/opasswd$"

    • Email alerting when using built-in alerting script template :

Dependencies

None

Example Playbook

Including an example of how to use your role (for instance, with variables passed in as parameters) is always nice for users too:

- hosts: myserver.mydomain.org
  become: true

  roles:
    - role: clamav
      freshclam_proxy:
        # note that proxy settings are here inherited :
        hostname: "{{ global_proxy.hostname }}"
        port: "{{ global_proxy.port }}"
        username: "{{ global_proxy.username }}"
        password: "{{ global_proxy.password }}"
      clamav_daemon_virus_event_mail_from: "Virus Alert <[email protected]>"
      # Email alert "To:" using list of adressses :
      clamav_daemon_virus_event_mail_to:
        - "[email protected]"
        - "[email protected]"
      # enable On Access scanning on the following paths :
      clamav_onaccess_include_paths:
        - "/root"
        - "/home"
        - "/tmp"
      # prevent infected virus files access :
      clamav_daemon_access_prevention: true
      # clamdscan max size parameters :
      clamav_daemon_max_scan_size: "950M"
      clamav_daemon_max_file_size: "950M"

More complex exemple adding some user allowed to launch clamdscan

- hosts: myserver.mydomain.org
  become: true

  roles:
    - role: clamav
      freshclam_proxy:
        # note that proxy settings are here inherited :
        hostname: "{{ global_proxy.hostname |default() }}"
        port: "{{ global_proxy.port |default() }}"
        username: "{{ global_proxy.username |default() }}"
        password: "{{ global_proxy.password |default() }}"
      clamav_daemon_virus_event_mail_from: "Virus Alert <[email protected]>"
      # Email alert "To:" using list of adressses :
      clamav_daemon_virus_event_mail_to:
        - "[email protected]"
        - "[email protected]"
      # enable On Access scanning on the following paths :
      clamav_onaccess_include_paths:
        - "/root"
        - "/home"
        - "/tmp"
      # prevent infected virus files access :
      clamav_daemon_access_prevention: true
      # clamdscan max size parameters :
      clamav_daemon_max_scan_size: "950M"
      clamav_daemon_max_file_size: "950M"

  tasks:
    # add some user and allow him to run clamdscan
    # group must exist before we can create user
    - name: "Create group {{ username }}"
      group:
        name: "{{ username }}"

    - name: "Create user {{ username }}"
      user:
        name: "{{ username }}"
        group:  "{{ username }}"
        createhome: yes
        shell: /bin/bash
        groups: "{{ clamav_daemon_socket_group }}"
        append: yes

License

WTFPL

Author Information

This role was created in 2019 by Jérôme Drouet