Better security auditing with Auditd and the Integrity Measurement Architecture

Sometimes event logs are not enough, and you need to supply your security systems with something more. For instance, you might want to improve the detection of anomalies or facilitate the hunt for an intruder on your network. Many commercial solutions are available for file integrity monitoring in Linux. However, some budgets don't allow for a large investment. The good news is that Linux systems have a great selection of open source tools for securing systems, and these tools provide a means for maintaining file integrity at low cost. The Integrity Measurement Architecture comes in handy.

Integrity Measurement Architecture (IMA) [1] is a component of the Linux kernel's integrity subsystem (see the "Components of the Integrity Subsystem" box.) IMA is responsible for calculating hashes of files before loading them, and it supports reporting on the hashes. The integrity subsystem also consists of an Extended Verification Module (EVM) that detects tampering with offline security attribute extensions (e.g., SELinux), which are the basis for clearance decisions of the Linux Security Modules (LSM) framework.

What Is IMA?

The main purpose of IMA is to detect if files have been accidentally or intentionally changed, evaluate the measurement of a file against a value stored as an extension attribute, and enforce the integrity of local files. These objectives are complemented by Mandatory Access Control (MAC) protections provided by LSM modules such as SELinux and Smack.

[...]

Use Express-Checkout link below to read the full article (PDF).

Buy this article as PDF

Express-Checkout as PDF
Price $2.95
(incl. VAT)

Buy Linux Magazine

SINGLE ISSUES
 
SUBSCRIPTIONS
 
TABLET & SMARTPHONE APPS
Get it on Google Play

US / Canada

Get it on Google Play

UK / Australia

Related content

  • Security Lessons: auditd

    The auditd tool can provide system logging capabilities to satisfy even the most paranoid users.

  • Core Technologies

    Look for intruders and study the health of your system with Linux auditing tools.

  • System Hardening with Lynis

    The Lynis testing tool looks for potential security problems and even suggests possibly remedies.

  • MITRE ATT&CK Workshop

    The MITRE ATT&CK website keeps information on attackers and intrusion techniques. We'll show you how to use that information to look for evidence of an attack.

  • UFW Firewall

    UFW takes the complexity out of iptables, which is great for beginners and is even good for experienced users who want to keep it simple and avoid hidden mistakes.

comments powered by Disqus
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters

Support Our Work

Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.

Learn More

News