Detecting malicious files using YARA rules
YARA is a powerful tool developed by Victor Manuel Alvarez (Twitter handle @plusvic
) from VirusTotal. With YARA, you can search files with specific content, and this is used by security professionals and malware researchers to identify and classify malicious files, but you can also use it to find any kind of content on a disk.
This tool is particularly helpful in incident response; for example, when you are in the triage process and you identify a file as potentially malicious, it will probably help you find that file on other devices across the network to size the compromise.
The creation of YARA rules is based on the identification of specific patterns of file contents, so you need to first get the suspicious file to analyze it and identify unique patterns that you could use to create the rule.
In the next subsection, you will learn the principal parts of the structure of a YARA rule.
Structure of a YARA rule
The structure...