If you are serious about cybersecurity today you absolutely must know everything there is no about IP scanners and how hackers and cyber criminals use port scanning as reconnaissance to get “under the skin” of online systems in an effort to find exploits they can use to break in.
On the surface, a port scanner – and port scanning in general – isn’t necessarily hostile or malicious. There are legitimate reasons to take advantage of IP scanners solutions on your own systems to spot exploits that may need to be patched and cybersecurity holes that need to be covered up.
But the people out there that are looking to break into online connected systems are almost always going to take advantage of a port scanner and port checker tool to find out if there is an easy way to get their foot in the door of your connected system, so to speak.
In an effort to better understand IP scanners and IP scanning in general we’ve put together this quick guide to help you out.
Let’s dive right in!
Everything Starts with a List of Active Hosts
Every IP scanner is going to first need a list of active hosts that they can actually scan. The scanning process itself is a technically specific way for the scanner to discover active hosts on network, mapping those individual hosts to IP addresses, and then analyzing specific responses to those individual IP addresses in an effort to find out whether or not there are any potential vulnerabilities that can be exploited.
Open port checker tools and open port scanner tools can also look for these kinds of vulnerabilities as soon a list of active hosts has been cultivated by IP scanner tools. The big piece of the puzzle is attaching those individual hosts on a network and mapping them to their own unique IP address, and that’s what these kinds of tools are designed to do.
Host Discovery Scanning
The process of using a port scanner or IP scanner to figure out what kinds of systems are up and running on a specific network is called host discovery, and this is usually the first step that cyber criminals and cyber thieves are going to take to run reconnaissance before a major attack.
Address Resolution Protocol scans and Internet Control Message Protocol scans can both be taken advantage of by the cyber criminals in an effort to really deep dive into the kinds of hosts and IP addresses that are active on any individual network.
Each individual type of scan is going to be looking for a specific subset of data points that allow the scanners to analyze independently, matching up the data sets that they are able to pull from the online port scanner to better understand whether or not specific vulnerabilities exist and if they do, what kind of vulnerability it is and how it may be exploited.
After a network scan has been completed and a list of active hosts has been drawn up it’s time for a port scanner to be run to identify how specific ports are being used by individual active hosts.
There are three real major categories that port checker tools are going to break individual hosts into, and they include:
- Open – This kind of response is going to be read as the host “listening” that particular port. You’re also almost always able to indicate the kind of service that was being used for this kind of scan with modern tools as well.
- Closed – This kind of response says that the individual host read the request that was sent but has responded back that there is no service listening on that port.
- Filtered – Port scanners can categorize individual ports as “filtered” when certain request packets are sent but absolutely no reply is received at all. This could mean that request packets are being filtered out and dropped behind a firewall, which means that there is an extra layer of protection that cyber criminals would have to jump over should they decide to go this route.
Preparation is Critical
Because our world is so hyper connected – and because cybersecurity is such a paramount focus these days – the overwhelming majority of modern online system are going to come with some kind of network intrusion detection set up and basic firewalls to protect you from IP scanner solutions, port checkers, and open port scanners.
At the same time, these pre-configured tools may or may not be 100% up-to-date and most modern cyber criminals are looking for ways to adapt their invasive tools to get around the security solutions on a daily basis.
There are a lot of pretty common detection rules that cyber criminals can get around just by altering the frequency of individual scans, by accessing individual ports out of order, or by actually “spoofing” the address that the IP scanner is using in the first place.
Your best chance at avoiding the kind of headache that can be caused by cyber criminals breaching your network is to get out in front of these issues and patch as many holes that exist in your network as humanly possible.
You want to eliminate as many easy roads into your system as possible, actively monitoring your platform to look for these kinds of issues so that you can cut them off before they are exploited.
In this way, using the same tools that cyber criminals would to find holes in your system – IP scanner solutions, online port scanners, open port scanners, etc. – is a great way to determine whether or not you are as secure as you believe your network to be.
This is a real “fight fire with fire” kind of approach but it’s one of the most effective as you will be getting the same kind of raw data and reconnaissance about your network that cyber criminals likely are as well.
Run these kinds of tools are regular basis and you will be able to find the easily exploitable holes in your network and can patch them up ASAP, finding new ones as they come along and taking them out of commission before they can be taken advantage of.