1 files changed, 157 insertions, 0 deletions
diff --git a/sliver-c2/tasks/harden.yaml b/sliver-c2/tasks/harden.yaml
new file mode 100644
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+++ b/sliver-c2/tasks/harden.yaml
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+- name: fail if system is not debian/ubuntu
+  ansible.builtin.assert:
+    that: "'debian' in ansible_facts.os_family.lower() or 'ubuntu' in ansible_facts.distribution.lower()"
+    fail_msg: "this playbook supports only debian-based systems"
+
+- name: remove snap and snapd
+  apt:
+    name:
+      - snap
+      - snapd
+    state: absent
+    purge: true
+
+- name: clean apt cache
+  apt:
+    autoclean: true
+
+- name: clear /etc/issue and /etc/motd
+  copy:
+    content: ""
+    dest: "{{ item }}"
+  loop:
+    - /etc/issue
+    - /etc/motd
+
+- name: check if /etc/update-motd.d directory exists
+  stat:
+    path: /etc/update-motd.d
+  register: motd_dir
+
+- name: find files in /etc/update-motd.d
+  find:
+    paths: /etc/update-motd.d
+    file_type: file
+  register: motd_files
+  when: motd_dir.stat.exists
+
+- name: remove execute permissions from all files in /etc/update-motd.d
+  file:
+    path: "{{ item.path }}"
+    mode: u-x,g-x,o-x
+  loop: "{{ motd_files.files }}"
+  when: motd_dir.stat.exists
+
+- name: enforce root-only cron/at
+  file:
+    path: "{{ item }}"
+    state: touch
+    owner: root
+    group: root
+    mode: '0600'
+  loop:
+    - /etc/cron.allow
+    - /etc/at.allow
+
+- name: remove deny files for cron and at
+  file:
+    path: "{{ item }}"
+    state: absent
+  loop:
+    - /etc/cron.deny
+    - /etc/at.deny
+
+- name: backup sshd_config
+  copy:
+    src: /etc/ssh/sshd_config
+    dest: "/etc/ssh/sshd_config.bak_{{ ansible_date_time.iso8601_basic }}"
+    remote_src: yes
+
+- name: harden sshd_config
+  copy:
+    dest: /etc/ssh/sshd_config
+    content: |
+      Port 22
+      Banner /etc/issue
+      UsePAM yes
+      Protocol 2
+      Subsystem sftp /usr/libexec/openssh/sftp-server
+      LogLevel verbose
+      PrintMotd no
+      AcceptEnv LANG LC_*
+      MaxSessions 5
+      StrictModes yes
+      Compression no
+      MaxAuthTries 3
+      IgnoreRhosts yes
+      PrintLastLog yes
+      AddressFamily inet
+      X11Forwarding no
+      PermitRootLogin yes
+      AllowTcpForwarding no
+      ClientAliveInterval 1200
+      AllowAgentForwarding no
+      PermitEmptyPasswords no
+      ClientAliveCountMax 0
+      GSSAPIAuthentication no
+      KerberosAuthentication no
+      IgnoreUserKnownHosts yes
+      PermitUserEnvironment no
+      ChallengeResponseAuthentication no
+      MACs hmac-sha2-512,hmac-sha2-256
+      Ciphers aes128-ctr,aes192-ctr,aes256-ctr
+
+- name: regenerate SSH host keys
+  shell: |
+    rm -f /etc/ssh/ssh_host_*key*
+    ssh-keygen -t ed25519 -f /etc/ssh/ssh_host_ed25519_key -N ""
+    ssh-keygen -t rsa -b 4096 -f /etc/ssh/ssh_host_rsa_key -N ""
+  args:
+    creates: /etc/ssh/ssh_host_ed25519_key
+  notify: restart ssh
+
+- name: enable unattended-upgrades
+  shell: dpkg-reconfigure --priority=low unattended-upgrades
+  args:
+    creates: /etc/apt/apt.conf.d/50unattended-upgrades
+
+- name: enable unattended-upgrades service
+  systemd:
+    name: unattended-upgrades
+    enabled: true
+    state: started
+
+- name: disable ipv6 in grub
+  lineinfile:
+    path: /etc/default/grub
+    regexp: '^GRUB_CMDLINE_LINUX='
+    line: 'GRUB_CMDLINE_LINUX="ipv6.disable=1"'
+  notify: update grub
+
+- name: allow ssh port and enable ufw
+  ufw:
+    rule: allow
+    port: 22
+    proto: tcp
+
+- name: enable ufw
+  ufw:
+    state: enabled
+    policy: deny
+
+- name: deploy custom fail2ban jail.local
+  template:
+    src: templates/jail.local.j2
+    dest: /etc/fail2ban/jail.local
+    owner: root
+    group: root
+    mode: '0644'
+  notify:
+    - restart fail2ban
+    - reload fail2ban
+
+- name: enable and start fail2ban
+  systemd:
+    name: fail2ban
+    enabled: true
+    state: started