42.zip

 42.zip is a notorious zip bomb, a maliciously crafted archive file only 42 kilobytes in size. It uses recursive compression with five nested layers of 16 zip files each, expanding to about 4.5 petabytes (over 4 million gigabytes) of data when fully unpacked, designed to overwhelm systems, scanners, or servers.

 

How It Works

This file exploits ZIP compression by repeating identical data (like null bytes) across nested archives, achieving extreme ratios—e.g., innermost files are ~4.3 GB each, multiplying exponentially outward. Unpacking triggers massive resource exhaustion, often crashing antivirus tools or denial-of-service attacks on naive decompressors. Modern software limits decompression depth or size to mitigate this.