Network security scanning tool Nessus (1)

Summary
Nessus is a powerful and easy-to-use remote security scanner that is free and extremely fast to update. The security scanner performs security checks on a specified network to identify whether the network has a security vulnerability that causes attacks by the opponent. The system is designed as the client/sever mode. The server is responsible for security checks and the client is used to configure and manage the server. The server also adopts the plug-in system, allowing users to add plug-ins that execute specific functions. This plug-in can perform faster and more complex security checks. In Nessus, a shared information interface is also used, called the knowledge base, which stores the results of the previous check. Check results can be saved in HTML, plain text, LaTeX, and other formats. (13:09:47)
1. About Nessus
Nessus is a powerful and easy-to-use remote security scanner that is free and extremely fast to update. The security scanner performs security checks on a specified network to identify whether the network has a security vulnerability that causes attacks by the opponent. The system is designed as the client/sever mode. The server is responsible for security checks and the client is used to configure and manage the server. The server also adopts the plug-in system, allowing users to add plug-ins that execute specific functions. This plug-in can perform faster and more complex security checks. In Nessus, a shared information interface is also used, called the knowledge base, which stores the results of the previous check. Check results can be saved in HTML, plain text, LaTeX, and other formats.
In future new versions, Nessus will support fast and faster security checks, and this check will consume less bandwidth, which may use the cluster technology to improve the system running efficiency.
Nessus has the following advantages:
It uses scanning based on multiple security vulnerabilities to avoid incomplete scanning.
It is free and offers a price advantage over commercial security scanning tools such as ISS.
Included in a survey on the most popular security tools that Nmap users participated in), Nessus ranked first in the competition with many commercial systems and open-source systems. The eyes of the masses are bright :).
Nessus features high scalability, ease of use, and powerful functions. It can scan multiple security vulnerabilities.
The Nessus security check is completely completed by the plug-ins plug-in. By the time of this article, the number of security check plug-ins provided by Nessus has reached 705 in 18 categories, and this number will increase in the future. For example, in the "useless services" class, the "Echo port open" and "Chargen" plug-ins are used to test whether the host is vulnerable to known echo-chargen attacks. In the "backdoors" class, the "pc anywhere" plug-in is used to check whether the host runs background programs such as BO and PcAnywhere, fortunately, this includes the recently raging CodeRed and its variants.
On the Nessus homepage, we not only detail the functions of various plug-ins, but also provide solutions to the problems. For more information about plug-in, see the http://cgi.nessus.org/plugins/dump.php3? Viewby = family
In addition to these plug-ins, Nessus also provides you with a scripting language that describes the attack type for additional security tests. This language is called Nessus Attack Script Language NSSL ), use it to compile the plug-in.
On the client, you can specify the machine running the Nessus service, the port scanner used, the content of the test, and the IP address range of the test. Nessus is based on multiple threads, so you can set the number of threads that the system is working at the same time. In this way, you can set the Nessus working configuration at the remote end. After the security detection is completed, the server returns the detection results to the client, which generates an intuitive report. In this process, because the content transmitted by the server to the client is a security weakness of the system, in order to prevent communication content from being monitored, you can also choose encryption during the transmission process.
2. Install Nessus
As mentioned above, Nessus consists of two parts: client and server. Let's first look at the Server installation.
2.1 Download and install
You can go to http://www.nessus.org/download.htmlto download the nessus的latest example. Nessus is divided into two parts: the server side and the client side, and the server side is divided into two versions: the stable version and the experimental version. We recommend that you download the stable version, if you are not too eager to see the new features in the experiment version.
Similarly, the nessus client has two versions: JAVA and C. The JAVA version can be run on multiple platforms. The C version supports Windows, with these two Client versions, you can perform security checks on any machine on the LAN.
Next let's take a look at the Server installation. The server has four installation packages:

nessus-libraries-x.x.tar.gzlibnasl-x.x.tar.gznessus-core.x.x.tar.gznessus-plugins.x.x.tar.gz

Install each software package in the above sequence. First, use tar-xzvf nessus-* To unbind the four packages. First, install the nessus lib Library:

cd nessus-libaries./configuremake

Run make install as root.
Install the other three software packages in the same order.
After installation, confirm to add the path of the installed library file to the/etc/ld. so. conf file:/usr/local/lib. If no, you only need to add this path to the file and execute ldconfig, so that you can find the Runtime Library when running nessus.
2.2 create a user
The Nessus server has its own user database, which imposes constraints on each user. Users can perform security scanning through the nessusd server throughout the network.
To create a user, follow these steps:

$ Nessus-adduserAddition of a new nessusd user ---------------------------- Login: admin // enter the Username Password: secret // user Password Authentification type (cipher or plaintext) [cipher]: cipher // select whether the authentication process is encrypted. Now enter the rules for this user, and hit ctrl-D once you are done :( the user can have an empty rule set) ^ DLogin: adminPssword: secretAuthentification: cipherRules: Is that OK (y/n )? [Y] yuser added

Nessus-adduser is a tool attached to Nessusd. After installation, this program is generated in the installation directory.
2.3 configure the Nessus server program Nessusd
Its configuration file is nessusd. conf, which is located in the/usr/local/etc/nessus/directory. In general, it is not recommended that you change the content unless you do need it.
2.4 start nessusd
After completing the preceding preparations, run the following command as the root user to start the server: nessusd-D.