Lynis es una herramienta de código abierto para Linux que nos permite hacer un escaneo de rootkits.
Instalación
Lo instalaremos en una máquina Kali Linux.
┌──(raul㉿kali)-[~]
└─$ sudo apt install lynis
[sudo] password for raul:
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following additional packages will be installed:
menu
The following NEW packages will be installed:
lynis menu
0 upgraded, 2 newly installed, 0 to remove and 28 not upgraded.
Need to get 637 kB of archives.
After this operation, 3,220 kB of additional disk space will be used.
Do you want to continue? [Y/n] Y
Una vez se haya instalado, podemos ver las opciones del programa si no le añadimos ningún parámetro.
┌──(raul㉿kali)-[~]
└─$ lynis
[ Lynis 3.0.7 ]
################################################################################
Lynis comes with ABSOLUTELY NO WARRANTY. This is free software, and you are
welcome to redistribute it under the terms of the GNU General Public License.
See the LICENSE file for details about using this software.
2007-2021, CISOfy - https://cisofy.com/lynis/
Enterprise support available (compliance, plugins, interface and tools)
################################################################################
[+] Initializing program
------------------------------------
Usage: lynis command [options]
Command:
audit
audit system : Perform local security scan
audit system remote <host> : Remote security scan
audit dockerfile <file> : Analyze Dockerfile
show
show : Show all commands
show version : Show Lynis version
show help : Show help
update
update info : Show update details
Options:
Alternative system audit modes
--forensics : Perform forensics on a running or mounted system
--pentest : Non-privileged, show points of interest for pentesting
Layout options
--no-colors : Don't use colors in output
--quiet (-q) : No output
--reverse-colors : Optimize color display for light backgrounds
--reverse-colours : Optimize colour display for light backgrounds
Misc options
--debug : Debug logging to screen
--no-log : Don't create a log file
--profile <profile> : Scan the system with the given profile file
--view-manpage (--man) : View man page
--verbose : Show more details on screen
--version (-V) : Display version number and quit
--wait : Wait between a set of tests
--slow-warning <seconds> : Threshold for slow test warning in seconds (default 10)
Enterprise options
--plugindir <path> : Define path of available plugins
--upload : Upload data to central node
More options available. Run '/usr/sbin/lynis show options', or use the man page.
No command provided. Exiting..
Uso
Para escanear nuestro sistema, utilizaremos el parámetro audit system.
┌──(raul㉿kali)-[~]
└─$ lynis audit system
[ Lynis 3.0.7 ]
################################################################################
Lynis comes with ABSOLUTELY NO WARRANTY. This is free software, and you are
welcome to redistribute it under the terms of the GNU General Public License.
See the LICENSE file for details about using this software.
2007-2021, CISOfy - https://cisofy.com/lynis/
Enterprise support available (compliance, plugins, interface and tools)
################################################################################
[+] Initializing program
------------------------------------
###################################################################
# #
# NON-PRIVILEGED SCAN MODE #
# #
###################################################################
NOTES:
--------------
* Some tests will be skipped (as they require root permissions)
* Some tests might fail silently or give different results
- Detecting OS... [ DONE ]
- Checking profiles... [ DONE ]
---------------------------------------------------
Program version: 3.0.7
Operating system: Linux
Operating system name: Kali Linux
Operating system version: Rolling release
Kernel version: 5.18.0
Hardware platform: x86_64
Hostname: kali
---------------------------------------------------
Profiles: /etc/lynis/default.prf
Log file: /home/raul/lynis.log
Report file: /home/raul/lynis-report.dat
Report version: 1.0
Plugin directory: /etc/lynis/plugins
---------------------------------------------------
Auditor: [Not Specified]
Language: en
Test category: all
Test group: all
---------------------------------------------------
- Program update status... [ NO UPDATE ]
[+] System tools
------------------------------------
- Scanning available tools...
- Checking system binaries...
[+] Plugins (phase 1)
------------------------------------
Note: plugins have more extensive tests and may take several minutes to complete
- Plugin: debian
[
[+] Debian Tests
------------------------------------
- Checking for system binaries that are required by Debian Tests...
- Checking /bin... [ FOUND ]
- Checking /sbin... [ FOUND ]
- Checking /usr/bin... [ FOUND ]
- Checking /usr/sbin... [ FOUND ]
- Checking /usr/local/bin... [ FOUND ]
- Checking /usr/local/sbin... [ FOUND ]
- Authentication:
- PAM (Pluggable Authentication Modules):
[WARNING]: Test DEB-0001 had a long execution: 17.553149 seconds
find: '/usr/lib/mysql/plugin/auth_pam_tool_dir': Permission denied
- libpam-tmpdir [ Not Installed ]
- File System Checks:
- DM-Crypt, Cryptsetup & Cryptmount:
- Software:
- apt-listbugs [ Not Installed ]
- apt-listchanges [ Not Installed ]
- needrestart [ Not Installed ]
- fail2ban [ Not Installed ]
]
[+] Boot and services
------------------------------------
- Service Manager [ systemd ]
- Checking presence GRUB2 [ FOUND ]
- Checking for password protection [ NONE ]
- Check running services (systemctl) [ DONE ]
Result: found 20 running services
- Check enabled services at boot (systemctl) [ DONE ]
Result: found 18 enabled services
- Check startup files (permissions) [ OK ]
- Running 'systemd-analyze security'
- ModemManager.service: [ MEDIUM ]
- NetworkManager.service: [ EXPOSED ]
- accounts-daemon.service: [ MEDIUM ]
- colord.service: [ EXPOSED ]
- cron.service: [ UNSAFE ]
- dbus.service: [ UNSAFE ]
- emergency.service: [ UNSAFE ]
- gdm.service: [ UNSAFE ]
- getty@tty1.service: [ UNSAFE ]
- haveged.service: [ PROTECTED ]
- lynis.service: [ UNSAFE ]
- open-vm-tools.service: [ UNSAFE ]
- plymouth-start.service: [ UNSAFE ]
- polkit.service: [ UNSAFE ]
- rc-local.service: [ UNSAFE ]
- rescue.service: [ UNSAFE ]
- rpc-gssd.service: [ UNSAFE ]
- rpc-statd-notify.service: [ UNSAFE ]
- rpc-svcgssd.service: [ UNSAFE ]
- rsyslog.service: [ UNSAFE ]
- rtkit-daemon.service: [ MEDIUM ]
- smartmontools.service: [ UNSAFE ]
- ssh.service: [ UNSAFE ]
- systemd-ask-password-console.service: [ UNSAFE ]
- systemd-ask-password-plymouth.service: [ UNSAFE ]
- systemd-ask-password-wall.service: [ UNSAFE ]
- systemd-fsckd.service: [ UNSAFE ]
- systemd-initctl.service: [ UNSAFE ]
- systemd-journald.service: [ PROTECTED ]
- systemd-logind.service: [ PROTECTED ]
- systemd-networkd.service: [ PROTECTED ]
- systemd-rfkill.service: [ UNSAFE ]
- systemd-timesyncd.service: [ PROTECTED ]
- systemd-udevd.service: [ MEDIUM ]
- udisks2.service: [ UNSAFE ]
- upower.service: [ PROTECTED ]
- user@1000.service: [ UNSAFE ]
- vgauth.service: [ UNSAFE ]
- wpa_supplicant.service: [ UNSAFE ]
[+] Kernel
------------------------------------
- Checking default run level [ RUNLEVEL 5 ]
- Checking CPU support (NX/PAE)
CPU support: PAE and/or NoeXecute supported [ FOUND ]
- Checking kernel version and release [ DONE ]
- Checking kernel type [ DONE ]
- Checking loaded kernel modules [ DONE ]
Found 79 active modules
- Checking Linux kernel configuration file [ FOUND ]
- Checking default I/O kernel scheduler [ NOT FOUND ]
- Checking for available kernel update [ OK ]
- Checking core dumps configuration
- configuration in systemd conf files [ DEFAULT ]
- configuration in etc/profile [ DEFAULT ]
- 'hard' configuration in security/limits.conf [ DEFAULT ]
- 'soft' configuration in security/limits.conf [ DEFAULT ]
- Checking setuid core dumps configuration [ DISABLED ]
- Check if reboot is needed [ NO ]
[+] Memory and Processes
------------------------------------
- Checking /proc/meminfo [ FOUND ]
- Searching for dead/zombie processes [ NOT FOUND ]
- Searching for IO waiting processes [ NOT FOUND ]
- Search prelink tooling [ NOT FOUND ]
[+] Users, Groups and Authentication
------------------------------------
- Administrator accounts [ OK ]
- Unique UIDs [ OK ]
- Unique group IDs [ OK ]
- Unique group names [ OK ]
- Password file consistency [ SUGGESTION ]
- Checking password hashing rounds [ DISABLED ]
- Query system users (non daemons) [ DONE ]
- NIS+ authentication support [ NOT ENABLED ]
- NIS authentication support [ NOT ENABLED ]
- Sudoers file(s) [ FOUND ]
- PAM password strength tools [ SUGGESTION ]
- PAM configuration files (pam.conf) [ FOUND ]
- PAM configuration files (pam.d) [ FOUND ]
- PAM modules [ FOUND ]
- LDAP module in PAM [ NOT FOUND ]
- Accounts without expire date [ OK ]
- Accounts without password [ OK ]
- Locked accounts [ OK ]
- Checking user password aging (minimum) [ DISABLED ]
- User password aging (maximum) [ DISABLED ]
- Checking Linux single user mode authentication [ OK ]
- Determining default umask
- umask (/etc/profile) [ NOT FOUND ]
- umask (/etc/login.defs) [ SUGGESTION ]
- LDAP authentication support [ NOT ENABLED ]
- Logging failed login attempts [ ENABLED ]
[+] Shells
------------------------------------
- Checking shells from /etc/shells
Result: found 14 shells (valid shells: 14).
- Session timeout settings/tools [ NONE ]
- Checking default umask values
- Checking default umask in /etc/bash.bashrc [ NONE ]
- Checking default umask in /etc/profile [ NONE ]
[+] File systems
------------------------------------
- Checking mount points
- Checking /home mount point [ SUGGESTION ]
- Checking /tmp mount point [ SUGGESTION ]
- Checking /var mount point [ SUGGESTION ]
- Query swap partitions (fstab) [ OK ]
- Testing swap partitions [ OK ]
- Testing /proc mount (hidepid) [ SUGGESTION ]
- Checking for old files in /tmp [ OK ]
- Checking /tmp sticky bit [ OK ]
- Checking /var/tmp sticky bit [ OK ]
- Mount options of / [ NON DEFAULT ]
- Mount options of /dev [ PARTIALLY HARDENED ]
- Mount options of /dev/shm [ PARTIALLY HARDENED ]
- Mount options of /run [ HARDENED ]
- Total without nodev:7 noexec:10 nosuid:5 ro or noexec (W^X): 10 of total 26
- Checking Locate database [ NOT FOUND ]
- Disable kernel support of some filesystems
[+] USB Devices
------------------------------------
- Checking usb-storage driver (modprobe config) [ NOT DISABLED ]
- Checking USB devices authorization [ ENABLED ]
- Checking USBGuard [ NOT FOUND ]
[+] Storage
------------------------------------
- Checking firewire ohci driver (modprobe config) [ NOT DISABLED ]
[+] NFS
------------------------------------
- Query rpc registered programs [ DONE ]
- Query NFS versions [ DONE ]
- Query NFS protocols [ DONE ]
- Check running NFS daemon [ NOT FOUND ]
[+] Name services
------------------------------------
- Checking search domains [ FOUND ]
- Searching DNS domain name [ UNKNOWN ]
- Checking /etc/hosts
- Duplicate entries in hosts file [ NONE ]
- Presence of configured hostname in /etc/hosts [ FOUND ]
- Hostname mapped to localhost [ NOT FOUND ]
- Localhost mapping to IP address [ OK ]
[+] Ports and packages
------------------------------------
- Searching package managers
- Searching dpkg package manager [ FOUND ]
- Querying package manager
[WARNING]: Test PKGS-7345 had a long execution: 12.472662 seconds
- Query unpurged packages [ FOUND ]
- Checking upgradeable packages [ SKIPPED ]
- Checking package audit tool [ NONE ]
- Toolkit for automatic upgrades [ NOT FOUND ]
[+] Networking
------------------------------------
- Checking IPv6 configuration [ ENABLED ]
Configuration method [ AUTO ]
IPv6 only [ NO ]
- Checking configured nameservers
- Testing nameservers
Nameserver: 8.8.8.8 [ OK ]
Nameserver: 8.8.4.4 [ OK ]
- Minimal of 2 responsive nameservers [ OK ]
- Checking default gateway [ DONE ]
- Getting listening ports (TCP/UDP) [ DONE ]
- Checking promiscuous interfaces [ OK ]
- Checking waiting connections [ OK ]
- Checking status DHCP client
- Checking for ARP monitoring software [ NOT FOUND ]
- Uncommon network protocols [ 0 ]
[+] Printers and Spools
------------------------------------
- Checking cups daemon [ NOT FOUND ]
- Checking lp daemon [ NOT RUNNING ]
[+] Software: e-mail and messaging
------------------------------------
[+] Software: firewalls
------------------------------------
- Checking iptables kernel module [ FOUND ]
- Checking host based firewall [ ACTIVE ]
[+] Software: webserver
------------------------------------
- Checking Apache (binary /usr/sbin/apache2) [ FOUND ]
Info: Configuration file found (/etc/apache2/apache2.conf)
Info: No virtual hosts found
* Loadable modules [ FOUND (119) ]
- Found 119 loadable modules
mod_evasive: anti-DoS/brute force [ NOT FOUND ]
mod_reqtimeout/mod_qos [ FOUND ]
ModSecurity: web application firewall [ NOT FOUND ]
- Checking nginx [ NOT FOUND ]
[+] SSH Support
------------------------------------
- Checking running SSH daemon [ NOT FOUND ]
[+] SNMP Support
------------------------------------
- Checking running SNMP daemon [ NOT FOUND ]
[+] Databases
------------------------------------
No database engines found
[+] LDAP Services
------------------------------------
- Checking OpenLDAP instance [ NOT FOUND ]
[+] PHP
------------------------------------
- Checking PHP [ NOT FOUND ]
[+] Squid Support
------------------------------------
- Checking running Squid daemon [ NOT FOUND ]
[+] Logging and files
------------------------------------
- Checking for a running log daemon [ OK ]
- Checking Syslog-NG status [ NOT FOUND ]
- Checking systemd journal status [ FOUND ]
- Checking Metalog status [ NOT FOUND ]
- Checking RSyslog status [ FOUND ]
- Checking RFC 3195 daemon status [ NOT FOUND ]
- Checking minilogd instances [ NOT FOUND ]
- Checking logrotate presence [ OK ]
- Checking remote logging [ NOT ENABLED ]
- Checking log directories (static list) [ DONE ]
- Checking open log files [ DONE ]
- Checking deleted files in use [ FILES FOUND ]
[+] Insecure services
------------------------------------
- Installed inetd package [ NOT FOUND ]
- Installed xinetd package [ OK ]
- xinetd status
- Installed rsh client package [ OK ]
- Installed rsh server package [ OK ]
- Installed telnet client package [ OK ]
- Installed telnet server package [ NOT FOUND ]
- Checking NIS client installation [ OK ]
- Checking NIS server installation [ OK ]
- Checking TFTP client installation [ SUGGESTION ]
- Checking TFTP server installation [ SUGGESTION ]
[+] Banners and identification
------------------------------------
- /etc/issue [ FOUND ]
- /etc/issue contents [ WEAK ]
- /etc/issue.net [ FOUND ]
- /etc/issue.net contents [ WEAK ]
[+] Scheduled tasks
------------------------------------
- Checking crontab and cronjob files [ DONE ]
[+] Accounting
------------------------------------
- Checking accounting information [ NOT FOUND ]
- Checking sysstat accounting data [ DISABLED ]
- Checking auditd [ NOT FOUND ]
[+] Time and Synchronization
------------------------------------
- NTP daemon found: systemd (timesyncd) [ FOUND ]
- Checking for a running NTP daemon or client [ OK ]
- Last time synchronization [ 261s ]
[+] Cryptography
------------------------------------
- Checking for expired SSL certificates [0/130] [ NONE ]
[WARNING]: Test CRYP-7902 had a long execution: 33.385395 seconds
- Kernel entropy is sufficient [ YES ]
- HW RNG & rngd [ NO ]
- SW prng [ YES ]
- MOR variable not found [ WEAK ]
[+] Virtualization
------------------------------------
[+] Containers
------------------------------------
[+] Security frameworks
------------------------------------
- Checking presence AppArmor [ FOUND ]
- Checking AppArmor status [ UNKNOWN ]
- Checking presence SELinux [ NOT FOUND ]
- Checking presence TOMOYO Linux [ NOT FOUND ]
- Checking presence grsecurity [ NOT FOUND ]
- Checking for implemented MAC framework [ NONE ]
[+] Software: file integrity
------------------------------------
- Checking file integrity tools
Cannot initialize device-mapper, running as non-root user.
- dm-integrity (status) [ DISABLED ]
Cannot initialize device-mapper, running as non-root user.
- dm-verity (status) [ DISABLED ]
- Checking presence integrity tool [ NOT FOUND ]
[+] Software: System tooling
------------------------------------
- Checking automation tooling
- Automation tooling [ NOT FOUND ]
- Checking for IDS/IPS tooling [ NONE ]
[+] Software: Malware
------------------------------------
- Malware software components [ NOT FOUND ]
[+] File Permissions
------------------------------------
- Starting file permissions check
File: /boot/grub/grub.cfg [ SUGGESTION ]
File: /etc/crontab [ SUGGESTION ]
File: /etc/group [ OK ]
File: /etc/group- [ OK ]
File: /etc/hosts.allow [ OK ]
File: /etc/hosts.deny [ OK ]
File: /etc/issue [ OK ]
File: /etc/issue.net [ OK ]
File: /etc/motd [ OK ]
File: /etc/passwd [ OK ]
File: /etc/passwd- [ OK ]
File: /etc/ssh/sshd_config [ SUGGESTION ]
Directory: /etc/cron.d [ SUGGESTION ]
Directory: /etc/cron.daily [ SUGGESTION ]
Directory: /etc/cron.hourly [ SUGGESTION ]
Directory: /etc/cron.weekly [ SUGGESTION ]
Directory: /etc/cron.monthly [ SUGGESTION ]
[+] Home directories
------------------------------------
- Permissions of home directories [ WARNING ]
- Ownership of home directories [ OK ]
- Checking shell history files [ OK ]
[+] Kernel Hardening
------------------------------------
- Comparing sysctl key pairs with scan profile
- dev.tty.ldisc_autoload (exp: 0) [ DIFFERENT ]
- fs.suid_dumpable (exp: 0) [ OK ]
- kernel.core_uses_pid (exp: 1) [ DIFFERENT ]
- kernel.ctrl-alt-del (exp: 0) [ OK ]
- kernel.dmesg_restrict (exp: 1) [ OK ]
- kernel.kptr_restrict (exp: 2) [ DIFFERENT ]
- kernel.modules_disabled (exp: 1) [ DIFFERENT ]
- kernel.perf_event_paranoid (exp: 3) [ OK ]
- kernel.randomize_va_space (exp: 2) [ OK ]
- kernel.sysrq (exp: 0) [ DIFFERENT ]
- kernel.unprivileged_bpf_disabled (exp: 1) [ DIFFERENT ]
- kernel.yama.ptrace_scope (exp: 1 2 3) [ DIFFERENT ]
- net.ipv4.conf.all.accept_redirects (exp: 0) [ DIFFERENT ]
- net.ipv4.conf.all.accept_source_route (exp: 0) [ OK ]
- net.ipv4.conf.all.bootp_relay (exp: 0) [ OK ]
- net.ipv4.conf.all.forwarding (exp: 0) [ OK ]
- net.ipv4.conf.all.log_martians (exp: 1) [ DIFFERENT ]
- net.ipv4.conf.all.mc_forwarding (exp: 0) [ OK ]
- net.ipv4.conf.all.proxy_arp (exp: 0) [ OK ]
- net.ipv4.conf.all.rp_filter (exp: 1) [ DIFFERENT ]
- net.ipv4.conf.all.send_redirects (exp: 0) [ DIFFERENT ]
- net.ipv4.conf.default.accept_redirects (exp: 0) [ DIFFERENT ]
- net.ipv4.conf.default.accept_source_route (exp: 0) [ DIFFERENT ]
- net.ipv4.conf.default.log_martians (exp: 1) [ DIFFERENT ]
- net.ipv4.icmp_echo_ignore_broadcasts (exp: 1) [ OK ]
- net.ipv4.icmp_ignore_bogus_error_responses (exp: 1) [ OK ]
- net.ipv4.tcp_syncookies (exp: 1) [ OK ]
- net.ipv4.tcp_timestamps (exp: 0 1) [ OK ]
- net.ipv6.conf.all.accept_redirects (exp: 0) [ DIFFERENT ]
- net.ipv6.conf.all.accept_source_route (exp: 0) [ OK ]
- net.ipv6.conf.default.accept_redirects (exp: 0) [ DIFFERENT ]
- net.ipv6.conf.default.accept_source_route (exp: 0) [ OK ]
[+] Hardening
------------------------------------
- Installed compiler(s) [ FOUND ]
- Installed malware scanner [ NOT FOUND ]
- Non-native binary formats [ FOUND ]
[+] Custom tests
------------------------------------
- Running custom tests... [ NONE ]
[+] Plugins (phase 2)
------------------------------------
================================================================================
Lynis security scan details:
Hardening index : 58 [########### ]
Tests performed : 241
Plugins enabled : 1
Components:
- Firewall [V]
- Malware scanner [X]
Scan mode:
Normal [ ] Forensics [ ] Integration [ ] Pentest [V] (running non-privileged)
Lynis modules:
- Compliance status [?]
- Security audit [V]
- Vulnerability scan [V]
Files:
- Test and debug information : /home/raul/lynis.log
- Report data : /home/raul/lynis-report.dat
================================================================================
Lynis 3.0.7
Auditing, system hardening, and compliance for UNIX-based systems
(Linux, macOS, BSD, and others)
2007-2021, CISOfy - https://cisofy.com/lynis/
Enterprise support available (compliance, plugins, interface and tools)
================================================================================
[TIP]: Enhance Lynis audits by adding your settings to custom.prf (see /etc/lynis/default.prf for all settings)
Después de hacer el escaneo nos habrá generado un archivo log en el directorio del usuario.
┌──(raul㉿kali)-[~]
└─$ ls
Desktop Documents Downloads lynis.log lynis-report.dat Music Pictures Public Templates Videos
┌──(raul㉿kali)-[~]
└─$ cat lynis.log
2022-09-25 14:32:20 Starting Lynis 3.0.7 with PID 2339, build date 2022-01-18
2022-09-25 14:32:20 ====
2022-09-25 14:32:20 ### 2007-2021, CISOfy - https://cisofy.com/lynis/ ###
2022-09-25 14:32:20 Checking permissions of /usr/share/lynis/include/profiles
2022-09-25 14:32:20 File permissions are OK
2022-09-25 14:32:20 Reading profile/configuration /etc/lynis/default.prf
2022-09-25 14:32:20 Action: created temporary file /tmp/lynis.yiLrnXkZOC
Este archivo es demasiado largo, ya que contiene cada operación y verificación que ha hecho de los archivos del sistema.
Conclusión
Lynis es un programa muy completo, puedes hacer un escaneo local o remoto. Además también puedes analizar archivos Dockerfile. Hay diferentes modos de auditorías, como forense o pentest. Por último, también cuenta con plugins adicionales para empresas.