Threat Level: green Handler on Duty: Johannes Ullrich

SANS ISC: ISC Feature of the Week: The 404Project - now with IP Mask - SANS Internet Storm Center SANS ISC InfoSec Forums

Participate: Learn more about our honeypot network

Sign Up for Free!   Forgot Password?
Log In or Sign Up for Free!
ISC Feature of the Week: The 404Project - now with IP Mask


We've covered the 404 Project in a previous feature and announced reports in

Today we feature an IP Mask for those who would like to obfuscate the IP for privacy or legal concerns. The parsing scripts have been tested to handle v1 format (without IP mask) or v2 (with mask) so backwards compatibility is ensured.


A quick summary explanation with example ranges has been added at

The full details are in the code block at

Simply copy/paste the new code, fill in the variables as before with the addition of updating $sIPMask if you want to obfuscate the IP or leave the default to pass the entire value unchanged. Possible masks include but not limited to:

  • 0xffffffff = (Default)
  • 0xffffff00 = (mask /24)
  • 0xffff0000 = (mask /16)
  • 0xff000000 = (mask /8)
  • 0x00ffffff = (mask first octet)
  • 0xff00ffff = (mask second octet)
  • etc...


Please send us a note if you encounter any problems or post suggestions or comments in the section below or send us any questions or comments in the contact form on
Adam Swanger, Web Developer (GWEB, GWAPT)
Internet Storm Center


86 Posts
Jul 26th 2012

Sign Up for Free or Log In to start participating in the conversation!