Running your first scan using NessusWX

The following is a simple how-to guide for installing,
configuring, and running your first vulnerability scan using the
NessusWX Windows client. The instructions do not include in
depth explanations as it is assumed that you are familiar with
benefits of using Nessus and have a general working knowledge of
Windows.

As with any software installation, your results may vary
depending on the machine operating system and patch levels being
used. The installation steps were conducted using of NessusWX
1.4.4 on several Windows operating systems and patch levels
including XP, 2000, and 2003 Server to insure accuracy. It is
recommended that the installation be conducted using the “admin”
account or equivalent to avoid rights issues.

Install NessusWX

• Download and save
  the self-extracting version of NessusWX for Intel platforms from
  http://nessuswx.nessus.org/ to a temp directory on your hard
  drive. (nessuswx-1.4.4-install.exe, 1413KB in size); type='disc'>Double-click NessusWX-1.4.4-install.Exe to start the
  installation process;
• If using XP SP2 you may be
  prompted with a warning message that the publisher could not be
  verified, click
• At the “Welcome to the
  Installation Wizard” screen click
• At the
  “License Agreement” screen read the license terms, check “Yes, I
  agree with all the terms of this license agreement”, click
  ;
• At the “Destination Folder” screen enter
  the desired location for NessusWX, or accept the default of
  C:Program FilesNessusWX, click ;
• At the
  “Setup Type” screen select “Binaries Only”, or if you wish the
  source files included select “Binaries & Source”, click ;

• At the “Program Group” screen select the desired
  program group, or leave at the default of NessusWX, click
  ;
• At the “Ready to Install the Program”
  screen click ;
• At the “Installation
  Complete” screen click .

If the installation process
completed successfully, you now have a NessusWX desktop icon and
Start/Programs/NessusWX menu listing.

Configuration of NessusWX

Before configuring the NessusWX client, you need some
information concerning the Nessus server you will be using.
Please contact you Nessus server administrator for assistance if
needed.

     Nessus server IP: _______________________

     Nessus port number: _____________________ (default is 1241)

     Max simultaneous hosts: __________________ (default is 16)

     Max security checks per host: ______________ (default is 10)

     Your Nessus login name: __________________

     Your Nessus login password: _______________

Maximum simultaneous hosts, and maximum security checks per
host, refers to the number simultaneous scans that will be
performed. It is possible to optimize a Nessus server to support
more then the default settings and to use a different port. If
in this information is not available or unknown use the default
values.

Your Nessus Server administrator has the ability to limit what
IP range(s) you can scan based on your login name. Speak with
your Nessus server administrator and determine what limits, if
any, have been established.

• Upon executing NessusWX you will be
  prompted with the “Settings” screen, “General” tab,requesting
  database directory information. By default NessusWX uses
  C:NessusDB to storescan result. The database location can be a
  network drive if you wish to store results on a network drive
  for security purposes. Select the defaults value or change to
  the desired directory, click
• If the
  directory you selected does not exist, you will be prompted with
  a creation message, click
• Select
  “Communications/Connect” menu option
  type='circle'>Change the default Server “Name”, from the default
  127.0.0.1, to the desired Nessus server; type='circle'>Change the default Server “Port Number”, from
  1241, to the desired Nessus server port if needed; type='circle'>By default, NessusWX selects TLSv1 as encryption
  option;
  • Select “Authentication by Password”
    radio button;
  • Check save password checkbox;

  • Change the default Authentication “Login”
    value to your Nessus login name;
  • Enter your
    Nessus login name password, click type='circle'>You will be prompted with New Server Certificate
    window displaying the Nessus server certificate information,
    click

If the userid/password information you entered is correct, you
will receive a brief message that NessusWX is downloading plugin
information. Upon download completion, something similar to the
following will be displayed at the bottom of the NessusWX screen:

     Using

     Connection with the server [xxx.xxx.xxx.xxx] established

     xxxx plugins loaded

     xxxx preferences received

     xxxx rules received

You now have a fully functioning copy of NessusWX installed,
have connected to a Nessus Server, and are ready to being
performing vulnerability scans.

Before You Scan

Before performing vulnerability scanning, a few cautions and
recommendations should be considered:

• Make sure you are acting within your
  authority. Most companies have strict policies about who can
  perform vulnerability scanning and on what equipment. Acting
  outside your authority with a vulnerability scanner could lead
  to your dismissal;
• Absent Nessus server based
  rules that limit what IP ranges you can test, obtain written
  permission on what you are and are not permitted to perform
  vulnerability test on;
• Vulnerability scanning
  can leave equipment in an unstable state. This is practically
  true if performing Denial of Service tests and/or testing
  systems are very poorly configured. Nessus vulnerability
  scanning is normally not destructive and rebooting the affected
  equipment will return it to the correct operational state; type='disc'>NessusWX has a selection for “Safe checks” that
  disables the most dangerous scripts from executing and instead
  relies on banners information to determine vulnerability rather
  than exploiting the real flaw. However, it is still possible to
  leave equipment in an unstable state;
• If your
  company uses an intrusion detection system, performing
  vulnerability scanning on the network will most likely trigger
  intrusion alerts. Vulnerability scanning is very “noisy” and
  easily detected by most intrusion detection systems; type='disc'>If you are performing vulnerability scans across the
  internet verify your ISP will not object, that your scanning
  will not trigger their intrusion detection system, and request
  documentation concerning scanning polices and rules that you
  must follow;
• Exercise common sense when
  performing vulnerability scans. For example, it’s most likely
  not a good idea to run a Denial of Services test on your core
  router during normal business hours;
• NEVER SCAN
  EQUIPMENT THAT YOU ARE NOT EXPRESSLY AUTHORIZED TO SCAN. Doing
  so could result in lawsuits, bad press, jail, ISP termination,
  and unemployment just to name a few. Running a Denial of
  Services test against your competitor’s web site for example,
  will most likely result in several unwanted events occurring
  once you and your company are identified as the cause.

Performing Your First Scan

To perform your first vulnerability scan, you must create a
Session (job) outlining the targets and scanning options desired.

• Click menu selection Session/New; type='disc'>You will be prompted to enter a session name or
  accept the default of “Session1″. Enter “First Scan”, leave
  “Define additional properties” checked, click ; type='disc'>At the “Session Properties – Test Scan”, click the
  “Targets” tab, then click ;
• At the “Add
  Target” screen you have the option of entering a single host, a
  subnet, or IP range depending on scanning needs. For our test
  session, select a single IP address and enter the IP or Host
  name of your workstation, click ;
• Click
  .
• Click the “Options” tab:
  type='circle'>Change “Maximum simultaneous” default value if
  needed;
  • Change “Security checks per host”
    default value if needed;
  • “General scan
    options/Enable plugin dependencies”. Nessus uses many plugins
    (tests) that require the use of other plugins to operate
    correctly. Checking this box permits Nessus to automatically
    enable dependencies as needed. For our test scan, “Enable plugin
    dependencies” should be checked;
  • “General scan
    options/Do reverse DNS lookups” simply performs a DNS lookup on
    the target to determine the host name. For our test scan, check
    “Do reverse DNS lookups”;
  • “General scan
    options/Safe checks”. As stated previously, Safe Checks disables
    the most dangerous scripts from executing and instead relies on
    banner information to determine vulnerability rather than
    exploiting the real flaw. For our test scan, leave “Safe checks”
    checked;
  • “General scan options/Optimize the
    test” lets Nessus avoid all apparently irreverent tests. For
    example, tests will not be conducted for web site unless a web
    site is detected. For our test scan, leave “Optimize the test”
    checked;
  • “General scan options/Resolve unknown
    services” will permit Nessus to resolve any unknown services
    that may be operating on the system. For our test scan, leave
    “Resolve unknown services” checked;
  • “Path to
    CGI’s”. Nessus has the ability to check for generic CGI
    vulnerabilities that may be present. For our test scan, leave
    “Path to CGI’s” at the default of “/cgi-bin”; type='circle'>“Interface options” permits you to limit the
    results that are displayed on the screen while scanning is
    occurring. For our test scan, leave both items unchecked to
    display the maximum amount of information; type='circle'>Click .
• Click the
  “Port scan” tab:
  • “Port range to scan”
    permits you to enter the ports Nessus will scan. For our test
    scan, we will use the default of “Privileged ports (1-1024)”;

  • “Port scanners” permits the use of a wide
    range of port scanners depending on your needs. For our test
    scan, leave the default of “Ping the report host” and “tcp
    connect scan” checked.
  • Click .
• Click the “Connection” tab will permit you to
  enter and store specifics about the Nessus server to be used for
  the session. Since we are currently connected to a specific
  Nessus server, no need exists to enter this information for our
  test scan;
• Click the “Plugins” tab:
  type='circle'>To test for system vulnerability we must enable
  plugins. Check the “Use session-specific plugin” checkbox. You
  will notice that currently “0 plugins currently are selected for
  execution”;
  • Click the “Select plugins” button
    to display the “Plugin List” screen. For our test scan, click
    the “Enable All” button, click , when prompted with “Do you
    wish to enable all port scanners as well”, click . You
    will notice that 2400 or so plugins are now selected for
    execution;
  • Click .
  type='disc'>Click the “Comments” tab and input any remarks you
  have concerning this session or its settings, then click to
  save your Session;

To execute the Session, right-click on the icon and then select
. When prompted at the “Execute Session” screen simply
click Execute and vulnerability scanning will commence.

Closing

Take some time, experiment, and learn what NessusWX and Nessus
have to offer. Patch systems and rescan to verify vulnerability
have been closed. Using NessusWX and Nessus will permit you to
find system vulnerabilities before hackers and virus/worm
writers have opportunity to do it for you.