42.zip is a notorious file that does not contain a virus but if you attempt to open it, you will fill your hdd to capicity in a matter of seconds rendering it useless until reformatted. It has been around int the wild for yuears and still appears in spam to this day.

WTH is it?

it is known in the hacker world as a zip bomb except this one is more like a nuclear warhead.

A zip bomb is usually a small file (up to 42 kilobytes) for ease of transport and to avoid suspicion. However, when the file is unpacked its contents are more than the system can handle.

One example of a Zip bomb is the file 42.zip which is a zip file consisting of 42 kilobytes of compressed data, containing five layers of nested zip files in sets of 16, each bottom layer archive containing a 4.3 gigabyte (4 294 967 295 bytes; ~ 3.99 GiB) file for a total of 4.5 petabytes (4 503 599 626 321 920 bytes; ~ 3.99 PiB) of uncompressed data. [3] This file is still available for download on various websites across the Internet. In many anti-virus scanners, only a few layers of recursion are performed on archives to help prevent attacks that would cause a buffer overflow, an out of memory condition, or exceed an acceptable amount of program execution time.

you read that right. a 42 kb zipped file opens to 4.5 petabytes.

source: http://en.wikipedia.org/wiki/Zip_bomb

I have a copy of this file if anyone wishes to play with it.