‫Hang on, before rushing in to start our first Nessus scan, I'd like to show you how to create our
‫own policies.
‫Policies allow you to create custom templates defining what actions are performed during a scan in the
‫Nessus Web interface click policies at the left side.
‫You see that good click the create a new policy link inside the policies page.
‫Now here we have a lot of scanners.
‫So in advance scan, all the options are chosen by us without any guidance or recommendations.
‫Basic network scan is generally suitable for any host.
‫Internal PCI network scan is designed for internal scans and it's based on PCI, DFS standard.
‫PCI says Payment Card Institute and data security standards simply one of the most important information
‫security standards.
‫So it looks like the days when this video was captured, that spectre and meltdown are the are really
‫new vulnerabilities.
‫So here there is a scan specialized where specter and meltdown vulnerabilities.
‫This clearly shows how up this is is here.
‫There's another scanner specific for Web applications.
‫So let's configure our own scan, click, advance scan first, give a name for your policy.
‫Now go to Discovery section, so we're in the host discovery page here, we have a ping, the remote
‫host option and the settings of the ping.
‫If we're going to use the data we collected with that map, we can close this ping scan because we already
‫have the lists of the hosts click port scanning to configure port scanning options.
‫The default value of the ports gain ranges will default.
‫I mean, Nessus will scan the ports, which is in its Nessa's services file.
‫Now I go to the terminal screen to analyze Inessa services file.
‫Let's find the file first.
‫Use the fine command to find the file means that the search will begin from the root directory.
‫Dasch name shows the name of the search file and hit Enter, and here it is, you can stop the search
‫using control keys.
‫I use the less command to see the content of the file.
‫Here are the ports protocols and the default services which use these ports.
‫Now I want to see the number of the lines of Nessa's services fail to understand how many ports are
‫scanned by default.
‫Cat command with a file name pipe that you see to see the word count.
‫The first number is the number of lines, a second one is a number of the words, and the last one is
‫the number of the characters.
‫So we can say that 9000 ports are scanned by default, which is a total of both TCP and UDP ports,
‫but what if you want to see the number of TCP ports scanned by default, you can use grep before W.S.
‫type cat filename PYT grep TCP pipe W.S..
‫You will see the number of TCP ports scanned by default.
‫There are about 4600 TCP ports now, if you want to scan for all ports, you should type one through
‫six five five three five in ports can range feel.
‫So here are the options to use S.H. service for a local board, a numerators, so let's have a short
‫break here.
‫If you have some credentials to scan some services in depth, you can define those credentials before
‫the scan.
‫So here, select your credentials tab and you see some services when you click the SS H, for example.
‫You will see the credential options, but let's remove this for now.
‫Now turn back to settings by clicking its tab.
‫We were in Discovery Port scanning page and here the port scanning options.
‫Since scan is selected by default, if you like, you can select TCP and or UDP scans as well.
‫Now go to the advanced section.
‫Safe checks are enabled by default.
‫So we can select scan IP addresses in a random order to make the scan a little more stealthy.
‫Let's look at the performance options.
‫We can reduce the number of Macs simultaneous hosts per scan to avoid delays and network traffic.
‫Max, a number of concurrent TCP sessions per host is not defined by default, we can define an upper
‫bound to keep the hosts safe.
‫And again, we may define a maximum number of concurrent TCP sessions per scan to keep the network traffic
‫safe.
‫Now look at the tabs on the top of the new policy page and you'll see the plug ins tab.
‫Right.
‫So here we have tons of plug ins used in Nessa's scans.
‫If you click one of the plug and families, you'll see all the plug ins of that family.
‫You see the total number of plug ins and a plug in family.
‫And here the plug ins.
‫You can click on Enabled next to a plug in to disable it.
‫Or if you want to disable an entire plug in family entirely, for example, denial of service, click
‫on Enable labeled next to the name of the plug in family click save.
‫And now we have our own Skåne policy.