If either of those strings is found, then the result of the rule is true. The rule shown above is named vendor and looks for the strings “Vendor name” and “Alias name”. The strings sections is where you can define the strings that will be looked for in the file.

To give the condition section a meaning you will also need a strings section. You can also include another rule as part of your conditions. Conditions are by design Boolean expressions and can contain all the usual logical and relational operators. It contains a Boolean expression that determines the result. This section specifies when the rule result is true for the object (file) that is under investigation. The condition section is the only one that is required. There is a list of YARA keywords that are not allowed to be used as an identifier because they have a predefined meaning. The identifier can contain any alphanumeric character and the underscore character, but the first character is not allowed to be a digit. It was developed with the idea to describe patterns that identify particular strains or entire families of malware.Įach rule has to start with the word rule, followed by the name or identifier. YARA was originally developed by Victor Alvarez of Virustotal and is mainly used in malware research and detection. YARA rules are a way of identifying malware (or other files) by creating rules that look for certain characteristics.

Malwarebytes manual rules