What is Active Scanning? Complete Guide to Network Security

Today all our digital work life depends on what networks we use. Network security is one of the primary factors to focus on when we discuss cyber security in businesses or for any personal use.

Network security consists of two types of scanning mainly Active scanning and Passive scanning. Active scanning is a technique used in network security to probe systems and networks for vulnerabilities. On the other hand, passive scanning merely listens for traffic coming from devices on the network.

In the previous article, we discussed the MITRE ATT&CK framework which consists of several tactics and techniques based on real-world observation. Further, it is composed of 10 different methods and Active Scanning is one of them. 

So, here we’ll cover the topic of active scanning, associated sub-techniques, and different special active scans in detail.

Let’s start discussing about some facts about active scanning in cybersecurity.

What is Active Scanning and Why Is It Used?

Active scanning is a technique in which you scan specific endpoints in an IT network to gather more precise data. Instead of passively gathering that information by “catching” it on the network’s traffic, active scanning involves sending packets or queries directly to certain assets.

Simply described, active scanning is a rapid deep scan performed on chosen targets to gather incredibly detailed data. These targets may be individual or collective devices.

It is used to locate, monitor, and administer IT or OT assets. In addition to gathering fundamental asset data, it also gathers specific information about users, installed software, patch levels, and other things.

It is helpful for a wide range of use cases, including vulnerability analyses, compliance audits, and other ITAM and SAM-related duties. 

But in many cases, these networks can be sniffed as it monitors all the data packets that go through the networks which is called network sniffing in cyber security.

For instance, a device that hasn’t had an update in a long or that someone who shouldn’t be accessing it is using. Therefore, these scans are perfect for aiding in asset investigations and enhancing a network’s cybersecurity.

Active Scanning vs. Passive Scanning

Let’s understand these terms more broadly through a table representation.

Feature	Active Scanning	Passive Scanning
Security Vulnerabilities	More effective at detecting vulnerabilities but requires firewall access and credentials, potentially risking data leaks.	Tests security without affecting performance, identifying vulnerabilities before they’re exploited, without added risk.
Deployment	Requires manual setup with user credentials and firewall adjustments, challenging in large environments.	Easily automated deployment, set up in about an hour, suitable for new employees or projects.
Resource Use	Can strain server resources and access sensitive data, potentially causing network overhead.	Gathers system intelligence without impacting performance, no need for active servers or installed agents.
Scalability	Effective but not easily scalable due to the need for user participation and manual setup.	Easily scalable, as no software installation is needed on devices, suitable for large networks.
Accuracy	Provides visibility into new connections but can miss areas if firewalls block access.	Offers a comprehensive, real-time view of your IT environment without any blind spots.

Active Scanning as per MITRE ATT&CK Framework

When adversaries target an organization, they may execute active reconnaissance scans to gather information. They may probe victim cloud infrastructure using active scans via network traffic, as opposed to other forms of reconnaissance that do not involve direct interaction.

There are different forms that adversaries may use to perform active scanning based on what information they want to gather. These scans can also be carried out in a variety of methods, such as by utilizing the built-in functionality of network protocols like ICMP.

These scans may offer opportunities for additional reconnaissance, such as searching publicly accessible websites and databases. They can also aid in building operational resources by developing or acquiring capabilities. Additionally, they may enable first access, for example, to external remote services or by exploiting public-facing applications.

Mitigation and Detection in Active Scanning

The term “Pre-Compromise” is used for any eligible mitigating actions that relate to methods employed before an adversary has Initial Access.

Active Scanning technique cannot be easily mitigated with preventive controls since it is based on behaviors performed outside of the scope of enterprise defenses and controls. Efforts should concentrate on reducing the volume and sensitivity of data that is accessible to outside parties.

In detection, the data source is “Network Traffic” which has two data components i.e. Network Traffic Content (NTC) and Network Traffic Flow (NTF). NTC monitors and analyzes traffic patterns and packet inspection associated with protocol(s) that do not follow the expected protocol standards and traffic flows. And, NTF monitors network data for unusual data flows. 

Sub-Techniques of Active Scanning

There are three sub-techniques associated with active scanning. They are;

Let’s briefly discuss the above sub-techniques.

1. Scanning IP Blocks

Try to understand the concept from the attacker’s point of view. They scan IP blocks and gather information then target the victim’s networks. 

These are such IP addresses that are in use as well as more specific details about the hosts assigned to those IP addresses. These scans may include and range from simple pings (ICMP requests and responses) to more nuanced scans that may reveal host software/versions via server banners or other network artifacts.

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2. Vulnerability Scanning

The attackers may try to scan the target’s IT environment for vulnerabilities. They check if the configuration of a target/host application properly aligns with the target of a specific exploit they may seek to use.

These scans are attempted to identify any commonly known or exploitable vulnerability present in the current environment. By using server banners, listening ports, or other network artifacts, vulnerability scans often collect information about currently running software and version numbers.

3. Wordlist Scanning

Infrastructure may be iteratively probed by adversaries using brute force and crawling methods. While using techniques similar to those used in brute force, this strategy aims to identify content and infrastructure rather than legitimate credentials.

​​The wordlists utilized in these scans may include terms about a particular piece of software as well as generic, frequently used names and file extensions. Adversaries may also use information obtained via various Reconnaissance techniques to construct unique, target-specific wordlists.

Know the Special Active Scans

There are two special active scans present. One is a Diagnostic Scan and the other is a Remediation Scan.

Diagnostic Scan assists with troubleshooting, downloading the diagnostic file and sending it to Tenable support. Whereas the remediation scan runs a follow-up active scan against existing active scan results. It evaluates a specific plugin against a specific target or targets where the related vulnerability was present in your earlier active scan.

Advantages of Performing Active Scanning

Smart IT managers are aware that completing security audits once a year is not sufficient since hackers are continually finding new ways to invade networks. Modern best practices recommend continuous monitoring i.e. active scanning to get a real-time perspective of networks and systems.

By executing active scanning, you will be aware of your organization’s entire attack surface and will be one step ahead of the hackers.

Stay One Step Ahead with the SysTools

After knowing about different attacks it is a bit obvious it is very required for every organization to stay protected from active versus passive scanning. SysTools is a leader in providing highly advanced data security and digital forensic solutions. These are designed to meet the dynamic needs of modern businesses.

Apart from the cyber security solutions we also worked in the cloud migration arena. Here we worked for different migration services like Rackspace to Office 365 migration and Google Workspace to Office 365 migration.

SysTools is devoted to operating when your organization needs it the most. So, if you are ready to protect your organization from probable security threats then reach out to our cyber experts for Managed Cybersecurity Services. We emphasize our expertise and experience in helping businesses stay safe from cyber threats.