An Introduction to Port Scans and Port Protection An Introduction to Port Scans and Port Protection
When it comes to cybercrime, an attacker’s primary goal is to gain access to your systems, using one of the many... An Introduction to Port Scans and Port Protection

When it comes to cybercrime, an attacker’s primary goal is to gain access to your systems, using one of the many tools in their arsenal to do so. Considering that a ransomware attack happens every 11 seconds in the United States, data breaches and system corruption are more common than ever right now.

One of the most basic forms of scouting out a company’s security defenses is through using a port scan. This tactic gives hackers information about your system, which they can then use to launch a more targeted attack.

First, What are Port Scans?

A port scan is a technique used by cybercriminals to find out information about a system they are going to target. It involves scanning through a network system and determining which ports are open, which are sending data, and which are receiving data.

Typically, cybercriminals will use port scanning in the early stages of when they’re planning on launching a cyberattack on a business. Port scans relay vital information to them, which will help them to inform their attack and target more specific resources. For example, a hacker could run a port scan on a company and quickly get a list of which computers are connected to the internet, which applications are being used on them each day, and even integral details about the system itself.

By working out these details, a hacker could potentially then figure out exactly what form of cyber defenses a business is using, then surpassing them with this knowledge. By doing your own port scan, you’re able to rapidly see which ports are open, hinting at which ports you should then protect from hackers.

If you turn to a port scan tool that does this for you, you’ll be able to give your cybersecurity team all the information they need to effectively protect your systems. 


What Techniques are used for Port Scans?

When a cybercriminal runs a port scan, there are typically three different scan formats that are used. Depending on the information that a hacker wants to gain, the type of port scan that they conduct will vary. 

That said, they will typically rely on one of these three:

  • Half-open SYN Scans – A SYN scan is used when a hacker wants to determine the particular status of a port. The half-open part of this title references the fact that they do this without actually establishing a full connection. Instead of creating a connection between systems, this form of the port scan will send a message, seeing which ports move to respond to the message. As a rapid form of scanning, this instantly tells an attacker which ports on your system are currently open, helping them find particular devices to target when they launch an attack.
  • XMAS Scans – Out of the three main formats for port scanning, XMAS scans are by far the hardest to detect. To detect and prevent these scans, you would have to have a designated tool that actively checks and defends your ports, which many businesses overlook. In fact, over 35% of all universities have open ports, so this just goes to show how vulnerable some institutions are. An XMAS scan will send a FIN packet, which will require a server to relay a message saying that there isn’t any more data available. If the port is closed, they will get this response. However, if no response is received, then the attacker will know that the port is currently live, then maneuver to target these systems. FIN packets are hardly ever monitored, making this incredibly difficult to catch manually.
  • Ping Sweeps – Finally, a ping sweep is where an ICMP (Internet Control Message Protocol) is sent to several servers, with a hacker waiting for responses. If a response is made, then this is a server that a hacker could potentially send a data packet to in the future. Ping scans are commonly run by cybersecurity firms in order to find areas where a firewall isn’t adequately covered. From there, they’ll attempt to remedy the situation.

While these are the most prominent form of ping scans, they are far from an exhaustive list, with port scanning being a deeply complex endeavor. While you can assign cybersecurity experts to focus directly on this problem, the invention of modern security tools has also led to port scanning being more accessible than ever.

If you turn to automatic security tools, you’ll be able to skip over the manual work of port scanning while keeping your system as safe as can be.

How to Prevent Port Scan Attacks

Preventing port scan attacks is normally covered if you have a comprehensive level of cloud security, as this is a very commonly used method of scouting for attackers. Due to this, check with your provider to see if they are currently covering your ports.

That said, there are a few manual ways that you can defend your ports:

  • Use TCP wrappers on your servers
  • Check the strength of your firewall (is it working?)
  • Uncover forgotten systems through your own port scans

Through these three methods, you’ll be able to create a great base level of protection for your business.

Final Thoughts

Port scans are a vital tool in every attacker’s handbook that you should be aware of. Instead of leaving your ports open and a breach down to chance, you should take steps to ensure that your business has effective strategies in place that prevent this method from being used upon you.

Within the vast majority of cloud security companies, you’ll be able to find a range of different port scanning defense tools, using similar tactics a hacker would use to then learn which ports need to be protected. As 24/7 support is provided through cloud security, you’ll be able to rest assured knowing that all of your ports are secure. 

About The Author on Port Scans –

Hazel Raoult is a freelance marketing writer and works with PRmention. She has 6+ years of experience in writing about business, entrepreneurship, technology, and all things SaaS. Hazel loves to split her time between writing, editing, and hanging out with her family.

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