A (Roshal Archive) file is a compressed package that bundles multiple files or folders into a single, smaller file. This format is popular for viral content because it allows for faster transfers and can be split into multiple parts. How to Safely Handle a "Viral" RAR Download

File Explorer is REALLY REALLY slow when dealing with RAR files

Viral files are often shared on untrustworthy platforms, which increases the risk of them containing malicious programs.