Ncrack is a high-speed network authentication cracking tool. It was built to help companies secure their networks by proactively testing all their hosts and networking devices for poor passwords. Security professionals also rely on Ncrack when auditing their clients. Ncrack was designed using a modular approach, a command-line syntax similar to Nmap and a dynamic engine that can adapt its behaviour based on network feedback. It allows for rapid, yet reliable large-scale auditing of multiple hosts.

Ncrack’s features include a very flexible interface granting the user full control of network operations, allowing for very sophisticated bruteforcing attacks, timing templates for ease of use, runtime interaction similar to Nmap’s and many more. Protocols supported include RDP, SSH, http(s), SMB, pop3(s), VNC, FTP, and telnet.



ncrack [Options] {target and service specification}


  Can pass hostnames, IP addresses, networks, etc.
  Ex:,,; 10.0.0-255.1-254
  -iX <inputfilename>: Input from Nmap's -oX XML output format
  -iN <inputfilename>: Input from Nmap's -oN Normal output format
  -iL <inputfilename>: Input from list of hosts/networks
  --exclude <host1[,host2][,host3],...>: Exclude hosts/networks
  --excludefile <exclude_file>: Exclude list from file
  Can pass target specific services in <service>://target (standard) notation or
  using -p which will be applied to all hosts in non-standard notation.
  Service arguments can be specified to be host-specific, type of service-specific
  (-m) or global (-g). Ex: ssh://,at=10,cl=30 -m ssh:at=50 -g cd=3000
  Ex2: ncrack -p ssh,ftp:3500,25,ssl
  -p <service-list>: services will be applied to all non-standard notation hosts
  -m <service>:<options>: options will be applied to all services of this type
  -g <options>: options will be applied to every service globally
  Misc options:
    ssl: enable SSL over this service
    path <name>: used in modules like HTTP ('=' needs escaping if used)
  Options which take <time> are in seconds, unless you append 'ms'
  (miliseconds), 'm' (minutes), or 'h' (hours) to the value (e.g. 30m).
  Service-specific options:
    cl (min connection limit): minimum number of concurrent parallel connections
    CL (max connection limit): maximum number of concurrent parallel connections
    at (authentication tries): authentication attempts per connection
    cd (connection delay): delay <time> between each connection initiation
    cr (connection retries): caps number of service connection attempts
    to (time-out): maximum cracking <time> for service, regardless of success so far
  -T<0-5>: Set timing template (higher is faster)
  --connection-limit <number>: threshold for total concurrent connections
  -U <filename>: username file
  -P <filename>: password file
  --user <username_list>: comma-separated username list
  --pass <password_list>: comma-separated password list
  --passwords-first: Iterate password list for each username. Default is opposite.
  -oN/-oX <file>: Output scan in normal and XML format, respectively, to the given filename.
  -oA <basename>: Output in the two major formats at once
  -v: Increase verbosity level (use twice or more for greater effect)
  -d[level]: Set or increase debugging level (Up to 10 is meaningful)
  --nsock-trace <level>: Set nsock trace level (Valid range: 0 - 10)
  --log-errors: Log errors/warnings to the normal-format output file
  --append-output: Append to rather than clobber specified output files
  --resume <file>: Continue previously saved session
  -f: quit cracking service after one found credential
  -6: Enable IPv6 cracking
  -sL or --list: only list hosts and services
  --datadir <dirname>: Specify custom Ncrack data file location
  -V: Print version number
  -h: Print this help summary page.


cyborg@cyborg:~$ ncrack,cl=10,at=1 -p 21 -m ftp:CL=1 -g CL=3 -sL -d

Starting Ncrack 0.01ALPHA ( ) at 2009-08-05 18:32 EEST

----- [ Timing Template ] -----
cl=7, CL=80, at=0, cd=0, cr=10, to=0

----- [ ServicesTable ] -----
SERVICE   cl  CL  at  cd  cr  to  ssl path
ftp:21    N/A 1   N/A N/A N/A N/A no  null
ssh:22    N/A N/A N/A N/A N/A N/A no  null
telnet:23 N/A N/A N/A N/A N/A N/A no  null
smtp:25   N/A N/A N/A N/A N/A N/A no  null
http:80   N/A N/A N/A N/A N/A N/A no  null
https:443 N/A N/A N/A N/A N/A N/A yes null

----- [ Targets ] -----
Host: ( )
  ssh:22 cl=10, CL=10, at=1, cd=0, cr=10, to=0, ssl=no, path=/
  ftp:21 cl=3, CL=1, at=0, cd=0, cr=10, to=0, ssl=no, path=/
  ftp:21 cl=3, CL=1, at=0, cd=0, cr=10, to=0, ssl=no, path=/

Ncrack done: 3 services would be scanned.
Probes sent: 0 | timed-out: 0 | prematurely-closed: 0

Ncrack finished.
1-10 12:11:55

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