RAR - what it is, common risks, and safe handling tips

RAR

What it is

RAR is a proprietary archive format that compresses one or more files into a single container with the .rar extension. It supports strong compression, error-recovery records, multi-part volumes, and self-extracting archives. Newer RAR versions add AES-256 encryption with password protection, so contents can be both smaller and locked.

Why it matters

RARs make large transfers faster and tidier, but they are also a common vehicle for malware. Encrypted archives can hide malicious payloads from casual inspection until a user extracts them.

How it works - quick tour

  • Compression: packs files with algorithms tuned for size.

  • Packaging: stores paths, timestamps, and optional recovery data.

  • Splitting: creates .part1.rar, .part2.rar for easier sharing.

  • Protection: optional password and AES encryption for contents and names.

Red flags

  • Unexpected RAR attachments from unknown senders.

  • Double extensions inside the archive like invoice.pdf.exe.

  • Archives that demand a password from the email body or a shady site.

  • Self-extracting RARs (.exe) that request admin rights.

Prevent it

  • Scan archives before opening and prefer extracting to a temporary folder.

  • Do not run executables directly from inside a RAR.

  • Be wary of password-protected archives you did not request.

  • Keep your archiver updated and block SFX extracts on locked-down systems.

    Glossary (A–Z)

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