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Vol. 1 · Ed. 2026
CyberGlossary
Entry № 1258

YARA Rule

What is YARA Rule?

YARA RuleA textual signature in the YARA language that describes byte, string, or behavioral patterns used to classify and detect malware samples and files.


YARA is a pattern-matching language and tool created by Victor Manuel Alvarez at VirusTotal (now Google) to help researchers describe families of malware. A YARA rule contains metadata, string definitions (text, hex, regex), and a boolean condition that combines them with logic, file properties, and modules such as PE, ELF, or Mach-O. Malware analysts, threat hunters, and incident responders run YARA against disk, memory dumps, mail attachments, sandboxes, and platforms like VirusTotal and EDR retro-hunt to triage suspicious files and pivot on campaigns. Rules can produce false positives, so authors typically tune them with known-good baselines.

Examples

  1. 01

    A YARA rule that matches Cobalt Strike Beacon configuration strings in process memory.

  2. 02

    Hunting for a custom backdoor across an EDR fleet using a high-confidence YARA rule on file write events.

Frequently asked questions

What is YARA Rule?

A textual signature in the YARA language that describes byte, string, or behavioral patterns used to classify and detect malware samples and files. It belongs to the Defense & Operations category of cybersecurity.

What does YARA Rule mean?

A textual signature in the YARA language that describes byte, string, or behavioral patterns used to classify and detect malware samples and files.

How does YARA Rule work?

YARA is a pattern-matching language and tool created by Victor Manuel Alvarez at VirusTotal (now Google) to help researchers describe families of malware. A YARA rule contains metadata, string definitions (text, hex, regex), and a boolean condition that combines them with logic, file properties, and modules such as PE, ELF, or Mach-O. Malware analysts, threat hunters, and incident responders run YARA against disk, memory dumps, mail attachments, sandboxes, and platforms like VirusTotal and EDR retro-hunt to triage suspicious files and pivot on campaigns. Rules can produce false positives, so authors typically tune them with known-good baselines.

How do you defend against YARA Rule?

Defences for YARA Rule typically combine technical controls and operational practices, as detailed in the full definition above.

What are other names for YARA Rule?

Common alternative names include: YARA signature, YARA-X.

Related terms

See also