The most well-known file matching this description is . It is a tiny 42,374-byte (approx. 42 KB) zip file that, when fully unzipped, expands to 4.5 petabytes of data.
: It consists of 5 levels of nested zip files. The bottom level contains 16 files, each being 4.3 GB of zeros, which compress incredibly well. Download 445K zip
It sounds like you're looking for the famous "44.5 KB" zip bomb (often rounded to 45K or 44K) and its technical write-up. The most well-known file matching this description is
: This is the definitive modern write-up. Fifield explains how to create a "non-recursive" zip bomb that achieves high compression ratios without nesting files, making it much more dangerous for scanners. You can find his full research and graphs on his personal site . : It consists of 5 levels of nested zip files
: Various cybersecurity blogs and "how-to-hack" communities on Reddit discuss the classic recursive structure and why it was so effective against early 2000s scanners.
: Do not attempt to decompress this file on a standard computer. Most modern antivirus programs and zip utilities will detect it as a "zip bomb" or "decompression bomb" and block it to prevent your system from crashing or running out of disk space. Recommended Write-ups
: For a visual breakdown of the math, searching for "Zip Bomb explained" on YouTube often leads to excellent technical summaries by channels like Computerphile .