Security experts at platforms like AskWoody recommend ensuring you are running WinRAR version 5.70 or higher , which completely removed the buggy library to fix the hole. How to Handle Your Old Archives Safely
We’ve all been there—digging through an old hard drive or a cloud backup and stumbling upon a file simply named old.rar . Maybe it’s a high school project, a collection of decade-old photos, or a backup of a game you loved. But before you double-click that archive, you should know that "old" in the world of file compression can sometimes mean "vulnerable." The 19-Year-Old Bug
Opening a time capsule of digital memories should be fun, not a security headache. Keep your software current, and those old .rar files will stay exactly what they should be: a harmless trip down memory lane. Topic: Just don't use WinRAR, OK? @ AskWoody
Back in 2019, a massive security flaw was discovered in WinRAR that had actually existed for nearly 19 years. The issue wasn't with the RAR format itself, but with a library called UNACEV2.DLL that WinRAR used to extract files in the older .ace format.
Use the latest version of WinRAR or switch to modern, open-source alternatives like 7-Zip or the built-in extraction tools in Windows 11.
Run a malware scan on any archive you don't clearly remember creating yourself.
Be wary of archives that contain executable files ( .exe , .scr , .vbs ) inside them, especially if they claim to be just "photos."
Hackers figured out they could rename a malicious .ace file to .rar . When a user with an outdated version of WinRAR (anything below version 5.70) tried to open it, the software would unknowingly trigger a "path traversal" vulnerability. This allowed the archive to drop a malicious file into your Windows Startup folder without you ever knowing. Why "Old" Matters
