CGI comms by Ciro Santilli 34 Updated +Created
We've come across a few shallow and stylistically similar websites on suspicious ranges with this pattern.
No JS/JAR/SWF comms, but rather a subdomain, and an HTTPS page with .cgi extension that leads to a login page. Some names seen for this subdomain:
  • secure.: most common
  • ssl.: also common
  • various other more creative ones linked to the website theme itself, e.g.:
    • musical-fortune.net has a backstage.musical-fortune.net
The question is, is this part of some legitimate tooling that created such patterns? And if so which? Or are they actual hits with a new comms mechanism not previously seen?
The fact that:
  • hits of this type are so dense in the suspicious ranges
  • they are so stylistically similar between on another
  • citizenlabs specifically mentioned a "CGI" comms method
suggests to Ciro that they are an actual hit.
In particular, the secure and ssl ones are overused, and together with some heuristics allowed us to find our first two non Reuters ranges! Section "secure subdomain search on 2013 DNS Census"