A YARA rule editor for Mac

What Tab.Noted checks as you type

When you edit .yar or .yara files, Tab.Noted checks your rules for common mistakes:

• Missing condition: sections
• Duplicate string identifiers
• String identifiers used in a condition but never defined
• Unbalanced braces

Problems get a red dot in the gutter and a red underline on the line. Click the dot to see the exact error. Turn checks on or off from View → Diagnostics.

Tips for keeping a YARA rule set tidy

• Name rules consistently. Pick one pattern, such as family, then file type, then behaviour, and stick to it.
• One purpose per rule. A rule that tries to catch several things is hard to tune and hard to explain.
• Fill in the meta section. Author, date, a one-line description and a reference make a rule easy to review later.
• Comment the intent. Say why a string matters, not just what it is.
• Compare versions before you ship. Diff the old and new rule to see exactly what changed.
• Test against known-good files. Run new rules over clean files to catch false positives early.

A small, well-labelled rule:

rule Example_PDF_With_JavaScript
{
    meta:
        description = "PDF that contains JavaScript"
        author = "Your name"
        date = "2026-11-08"

    strings:
        $pdf = "%PDF"
        $js  = "/JavaScript"

    condition:
        $pdf at 0 and $js
}