.rar files are often overlooked in large directories compared to massive .iso or .zip files.

It looks like a personal file an employee might have saved.

Fast forward to the 2020s, and the name "Cool.rar" has taken on a much darker meaning. According to reports from Ars Technica , hackers targeting Microsoft Exchange servers used a custom backdoor to steal sensitive data.

The choice of name is likely a form of "security through obscurity."