dnmap is a framework to distribute nmap scans amount several clients. Basically it reads a file with nmap commands already created and send those commands to each client connected to it.
The framework use a client/server architecture. The server knows what to do and the clients do it. All the logic and statistics are managed in the server. Nmap output is stored on both server and client. This is not a new architecture, and it is commonly used by botnets. If fact, this can be seen as a friendly nmap botnet
1- Put some nmap commands on a file like commands.txt
2- Start the dnmap_server
./dnmap_server -f commands.txt
3- Start any number of clients
./dnmap_client -s -a
The server will start to give nmap commands to the clients and results will be stored on both sides.
Features of the framework
– Clients can be run on any computer on Internet. Do not have to be local cluster or anything.
– Is uses TLS protocol for encryption.
– If the server gets down, clients continue trying to connect until the server gets back online.
– If the server gets down, when you put it up again it will send commands starting from the last command given before the shutdown. You do not need to remember where it was.
– You can add new commands to the original file without having to stop the server. The server will read them automatically.
– If some client goes down, the server will remember which command it was executing and it will re-schedule it for later.
– It will store every detail of the operations in a log file.
– It shows real time statistics about the operation of each client, including:
– Number of commands executed
– Last time seen
– Version of the client
– If the client is being run as root or not.
– It calculates the amount of commands executed per minute
– The historic average of the amount of commands executed per minute
– The status of the client (Online, Offline, Executing or Storing)
– You can choose which port to use. Defaults to 46001
– If the server gets down, it keeps connecting to it until it gets up again.
– Strip strange characters from the command sent by the server. Tries to avoid command injection vulns.
– It only executes the nmap command. It deletes the command send by the server and changes it by a known nmap binary in the system.
– You can pick an alias for your user.
– You can change which port to connect to.
– If the command sent by the server does not have a -oA option, the client add it anyway to the command, so it will always have a local copy of the output.
Sample output of the server
=| MET:5:43:32.837276 | Amount of Online clients: 2 |=
Alias #Commands Last Time Seen (time ago) UpTime Version Euid RunCmdXMin AvrCmdXMin Status
test1 765 Mar 11 21:35:02 ( 0’12”) 4h 6m 0.3 0 5.2 4.6 Executing
test2 698 Mar 11 21:34:59 ( 0’14”) 5h43m 0.3 0 2.0 3.2 Executing
Here MET means Mission Elapsed Time (http://en.wikipedia.org/wiki/Mission_Elapsed_Time).
This framework is NOT intended to be secure or to be used by people you do not trust. As the client will execute any nmap command you send, the client is trusting you. This was created so your friends can help you in the scan, or to use all your computers at the same time.
The client does not need to be run as root, but be aware that most nmap scan types need the client to be run as root. If some of your clients are not root, you can still send them TCP connect type of scans for example. But this should be done by you in the nmap commands file.
About nmap file commands creation
Nmap is a great tool and it can manage large scans quite well. It is not wise to send only one port and one host to each of your clients. You would want to send at least one host with a lot of ports to each client. Or one different network to each client. If you divide the commands too much the distributed scan will be slower that one unique computer.
Example commands in the file that are OK:
nmap -sS -p22 192.168.1.0/24 -v -n -oA 192.168.1.0
nmap -sS -p22 192.168.2.0/24 -v -n -oA 192.168.3.0
nmap -sS -p22 192.168.3.0/24 -v -n -oA 192.168.4.0
nmap -sP -p22 192.168.3.0/24 -v -n -oA 192.168.4.0
nmap -sS –top-ports 100 192.168.3.3 -v -n -oA 192.168.3.3.top100
nmap -sS –top-ports 100 192.168.3.4 -v -n -oA 192.168.3.4.top100
nmap -sS –top-ports 100 192.168.3.5 -v -n -oA 192.168.3.5.top100
Example commands in the file you should avoid:
nmap -sS -p22 192.168.1.1 -v -n -oA 192.168.1.1
nmap -sS -p22 192.168.1.2 -v -n -oA 192.168.1.2
nmap -sS -p22 192.168.1.3 -v -n -oA 192.168.1.3