Nested Zip Mitigation

This file is public domain and provided as-is. There are no guarantees. Use at your own risk.

This script was stirred up to be able to separate nested zip attachments from the mail flow of an MDA.

Steps:
Isolate the message in question from the mail stream by MD content filter rule "If message has file like *.zip then move ...".
Decompose the message to its parts (body, attachments...).
Check content list of zip files for more zip files and move message according to outcome.

We are not interested in the third or fourth level of zipped zip files. The mere fact that we have been sent a nested zip is to be seen as a fraudulent act alone and therefor is sufficient to deny delivery to the inculpable and clueless.

Depending on the lag your users can afford, the script should be called by the Windows task scheduler once in a while. I tend to call it 24/7 every 5 minutes.

Tools: (needed in the system search path i.e. must work from every cmd prompt)
unzip: http://www.info-zip.org/
uud64win: http://www.marks-lab.com/
grep: http://gnuwin32.sourceforge.net/packages/grep.htm

Best regards
Udo