Performing Your First Scan

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

• Click menu selection Session/New;
• You will be prompted to enter a session name or accept default of "Session1". Enter "First Scan", leave "Define additional properties" checked, click <Create>;
• At "Session Properties - Test Scan", click "Targets" tab, then click <Add>;
• At "Add Target" screen you have 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 IP or Host name of your workstation, click <Ok>;
• Click <Apply>.
• Click "Options" tab:
  • 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 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 target to determine host name. For our test scan, check "Do reverse DNS lookups";
  • "General scan options/Safe checks". As stated previously, Safe Checks disables most dangerous scripts from executing and instead relies on banner information to determine vulnerability rather than exploiting real flaw. For our test scan, leave "Safe checks" checked;
  • "General scan options/Optimize 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 test" checked;
  • "General scan options/Resolve unknown services" will permit Nessus to resolve any unknown services that may be operating on system. For our test scan, leave "Resolve unknown services" checked;
  • "Path to CGI’s". Nessus has ability to check for generic CGI vulnerabilities that may be present. For our test scan, leave "Path to CGI’s" at default of "/cgi-bin";
  • "Interface options" permits you to limit results that are displayed on screen while scanning is occurring. For our test scan, leave both items unchecked to display maximum amount of information;
  • Click <Apply>.
• Click "Port scan" tab:
  • "Port range to scan" permits you to enter ports Nessus will scan. For our test scan, we will use default of "Privileged ports (1-1024)";
  • "Port scanners" permits use of a wide range of port scanners depending on your needs. For our test scan, leave default of "Ping report host" and "tcp connect scan" checked.
  • Click <Apply>.
• Click "Connection" tab will permit you to enter and store specifics about Nessus server to be used for session. Since we are currently connected to a specific Nessus server, no need exists to enter this information for our test scan;
• Click "Plugins" tab:
  • To test for system vulnerability we must enable plugins. Check "Use session-specific plugin" checkbox. You will notice that currently "0 plugins currently are selected for execution";
  • Click "Select plugins" button to display "Plugin List" screen. For our test scan, click "Enable All" button, click <Yes>, when prompted with "Do you wish to enable all port scanners as well", click <Close>. You will notice that 2400 or so plugins are now selected for execution;
  • Click <Apply>.
• Click "Comments" tab and input any remarks you have concerning this session or its settings, then click <Ok> to save your Session;

To execute Session, right-click on icon and then select <Execute>. When prompted at "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.