If you are working with legacy devices (like the iPhone 3G, iPhone 3GS, or iPhone 4) and trying to install custom firmware, here is the standard process for using this utility: :
A zip file is a type of compressed file that contains one or more files or folders. In this case, the zip file likely contains the ireb tool and related files. ireb 40x 41 421 rc3zip link
If you accidentally downloaded the file, upload it to (without opening it). It will scan with 60+ antivirus engines. If you are working with legacy devices (like
: Jailbreaking can potentially void your warranty and may have legal implications depending on your country. Ensure you're aware of these factors. It will scan with 60+ antivirus engines
If you clicked the ireb 40x 41 421 rc3zip link , downloaded the file, and executed its contents: