Summary
Checks if a host is infected with Conficker.C or higher, based on Conficker's peer to peer communication.
When Conficker.C or higher infects a system, it opens four ports: two TCP and two UDP. The ports are random, but are seeded with the current week and the IP of the infected host. By determining the algorithm, one can check if these four ports are open, and can probe them for more data.
Once the open ports are found, communication can be initiated using Conficker's custom peer to peer protocol. If a valid response is received, then a valid Conficker infection has been found.
This check won't work properly on a multihomed or NATed system because the open ports will be based on a nonpublic IP. The argument 'checkall' tells Nmap to attempt communication with every open port (much like a version check) and the argument 'realip' tells Nmap to base its port generation on the given IP address instead of the actual IP.
By default, this will run against a system that has a standard Windows port open (445, 139, 137).
The arguments 'checkall' and 'checkconficker' will both perform checks regardless of which port is open, see the args section for more information.
Note: Ensure your clock is correct (within a week) before using this script!
The majority of research for this script was done by Symantec Security Response, and some was taken from public sources (most notably the port blacklisting was found by David Fifield). A big thanks goes out to everybody who contributed!
SYNTAX:
smbport: Override the default port choice. If 'smbport' is open, it's used. It's assumed to be the same protocol as port 445, not port 139. Since it probably isn't possible to change Windows' ports normally, this is mostly useful if you're bouncing through a relay or something.
checkall: If set to '1' or 'true', attempt
to communicate with every open port.
randomseed: Set to a value to change the filenames/service names that are randomly generated.
checkconficker: If set to '1' or 'true', the script will always run on active hosts, it doesn't matter if any open ports were detected.
smbbasic: Forces the authentication to use basic security, as opposed to 'extended security'. Against most modern systems, extended security should work, but there may be cases where you want to force basic. There's a chance that you'll get better results for enumerating users if you turn on basic authentication.
realip: An IP address to use in place of the one known by Nmap.
smbsign: Controls whether or not server signatures are checked in SMB packets. By default, on Windows, server signatures aren't enabled or required. By default, this library will always sign packets if it knows how, and will check signatures if the server says to. Possible values are:
- 'force': Always check server signatures, even if server says it doesn't support them (will probably fail, but is technically more secure).
- 'negotiate': [default] Use signatures if server supports them.
- 'ignore': Never check server signatures. Not recommended.
- 'disable': Don't send signatures, at all, and don't check the server's. not recommended. More information on signatures can be found in 'smbauth.lua'.