It’s a link to the famous 42.zip:

“Recursive bombs contain multiple nested archives that are unpacked one after another. An attack using such a file succeeds only if the attacked program supports recursive unpacking. A classic example of a recursive bomb is 42.zip, a file consisting of six layers of nested archives. It is just 42 kilobytes compressed, but after unpacking all the layers its size increases to 4.5 petabytes (4.5 million gigabytes). Recursive zip bombs also include zip quines — archives containing a copy of themselves, resulting in endless unpacking.”