What Exactly is Nmap, and What Can You Do With it?
Nmap (Network Mapper) is a free and open source program for vulnerability detection, port scanning, and network mapping. Despite the fact that it was established in 1997, Nmap remains the gold standard against which all other comparable programs, commercial or open source, are measured.
Nmap’s dominance has been maintained by a wide community of developers and programmers who assist to maintain and upgrade it. The Nmap community says that the program, which is available for free to everyone, is downloaded thousands of times each week.
It may be adjusted to function in most customized or highly specialized contexts because of its flexible, open source code base. Nmap distributions for Windows, Mac, and Linux are available, but Nmap also supports less popular or older operating systems such as Solaris, AIX, and AmigaOS. The source code is accessible in the following languages: C, C++, Perl, and Python.
Nmap 7.90, released in October 2020, includes over 70 bug fixes and enhancements, as well as significant build system changes and code quality improvements.
You can download Zenmap from here
What is Zenmap?
Initially, users are required to have extensive programming abilities or at least be familiar with console commands or non-graphical interfaces in order to install Nmap. That has recently changed with the release of the Zenmap utility for Nmap, which provides a graphical interface that makes starting the program and reviewing the returned results much easier.
Zenmap was designed to be user-friendly for novices. Zenmap, like Nmap, is free, and the source code is open and accessible to anybody who wants to use or change it.
Here are some of the features that Zenmap provides: Frequently used scans may be stored as profiles and performed again and again. A command maker enables you to create Nmap command lines interactively. Scan findings may be kept and retrieved at a later time. Scan results that have been saved may be compared to discover how they vary. Recent scan results may also be saved in a searchable database.
How does Nmap function?
Port scanning is at the core of Nmap. It works by having users create a list of targets on a network about which they wish to learn more. Users are not required to name particular targets, which is beneficial since most administrators do not have a comprehensive view of everything that is utilizing their network’s possibly hundreds of ports. Instead, they create a list of ports to scan.
It’s also feasible to scan all network ports, albeit this might take a long time and use a lot of available bandwidth. Furthermore, depending on the sort of passive protections in place on the network, such a huge port scan would very certainly generate security alarms. As a result, most users use Nmap in smaller deployments or split their network into sections for scheduled scanning over time.
Users may regulate the depth of each scan in addition to setting up a range of objects to be scanned. A light or restricted scan, for example, may yield information regarding which ports are open and which have been blocked due to firewall settings. More extensive scans might also collect data on the kind of devices that are utilizing those ports, the operating systems they are running, and even the services that are active on them. Nmap may also uncover more detailed information, such as the version of the found services. As a result, it’s ideal for detecting vulnerabilities and aiding with patch management efforts.
Controlling the scans used to require console commands, which, of course, took some knowledge. However, the new Zenmap graphical interface makes it simple for almost anybody, with or without prior training, to tell Nmap what they want it to uncover. Meanwhile, professionals may continue to utilize their existing console commands, making it a helpful tool for both experts and beginners.
Is there a security risk in using Nmap?
While it is possible to argue that Nmap is an ideal hacking tool, many of the deeper scan operations need root access and capabilities. Someone from the outside cannot just point Nmap at a target network that they do not have access to and expect it to miraculously reveal weaknesses for them to attack. Not only that, but any defensive or network monitoring technologies would raise a serious security warning in response to the effort.
That is not to argue that Nmap cannot be hazardous in the wrong hands, particularly if used by a rogue system administrator or someone using stolen credentials. This was proven in Oliver Stone’s 2016 film Snowden (another film that uses Nmap), which was about the suspected traitor Edward Snowden.
What exactly does Nmap do?
When used correctly, Nmap may be very useful for improving and safeguarding networks and information. The application collects and compiles all of the return data supplied back by Nmap-scanned ports. Based on that data, there are several primary actions that most consumers utilize the tool to assist with. They are as follows:
Network Mapping: This is the primary reason Nmap was established, and it is still one of its most popular applications. Nmap’s host discovery feature will detect the sorts of devices that are actively utilizing scanned ports. Servers, routers, switches, and other devices are included. Users may also observe how those devices are linked together and how they make a network map.
Port Rules Discovery: Even with a low-level scan, Nmap can readily determine if a port is open or closed by anything like a firewall. In fact, while developing firewalls, many IT experts utilize Nmap to double-check their work. They can determine if their rules are having the intended impact and whether their firewalls are functioning effectively.
Shadow IT Hunting: Nmap can be used to identify things that should not be on a network because it discovers the type and location of devices on a network. These devices are referred to as shadow IT since their existence on a network is not formally permitted and is sometimes purposefully disguised. Shadow IT is harmful since it is not part of a security assessment or program. For example, if someone discreetly installs an Xbox gaming server on a business network, it might not only drain bandwidth but also serve as a launchpad for an attack, particularly if it is not kept up to date with all the latest security updates.
Operating System Detection: Nmap can detect the operating systems that are running on found devices using a method known as OS fingerprinting. This often provides information on the device’s vendor (Dell, HP, etc.) and the operating system. A thorough Nmap scan may even reveal information like the OS patch level and the device’s projected uptime.
Service Discovery: Nmap’s ability to find services lifts it beyond the level of a standard mapping tool. Instead of merely identifying the existence of a device, users may initiate a deeper scan to determine what roles found devices are doing. This includes determining if they are serving as a mail server, a web server, a database repository, a storage device, or something else. Nmap may also report on which individual apps are running and what version of those applications is being utilized, depending on the scan.
What is Nmap’s future?
Despite being 25 years old, the Nmap tool is still evolving. It is carefully maintained, like other supposedly outdated technologies like Ethernet or Spanning Tree, by an active community of professionals who keep it relevant and up to date. In the case of Nmap, that community includes its extremely active founder, who is still known online as Fyodor.
Other improvements, like the new Zenmap tool, make it even more helpful, particularly for individuals who dislike interacting with consoles or command lines. Zenmap’s graphical interface enables users to easily set up targets and arrange desired scans with a few mouse clicks. This will help Nmap get a more extensive user base.
Last Words...
Finally, although there are many other programs that can accomplish comparable jobs these days, none of them have the track record that Nmap has. Furthermore, Nmap has always been entirely free and available for download. Because of all of these considerations, it’s almost certain that Nmap will be just as valuable and important in the next 25 years as it has been in the previous quarter-century.
References
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