related to specific security tokens or user sessions.
Do you have a or service that recently crashed or performed an update?
This alphanumeric string appears to be a (Universally Unique Identifier), which is often used by software systems to generate unique filenames for: Log files or diagnostic reports sent to technical support.
created during a software update or installation. Database exports or automated backups.
To help you figure out what this is, could you share (e.g., in a specific program's folder, an email attachment, or a download directory)? Knowing the approximate size of the RAR or what software you were using when it appeared would also be very helpful.