Regex Tester & Validator

This regex matches various system identifiers and special account names. It captures standard UUIDs (8-4-4-4-12 hex format), usernames or accounts that start with an underscore followed by at least three characters, and strings that either start or end with a dollar sign (commonly Windows machine accounts like `PC$` or hidden administrative shares). It is excellent for parsing system logs, extracting Active Directory objects, or identifying service accounts in security audits.