Book Image

Practical Network Scanning

By : Ajay Singh Chauhan
Book Image

Practical Network Scanning

By: Ajay Singh Chauhan

Overview of this book

Network scanning is the process of assessing a network to identify an active host network; same methods can be used by an attacker or network administrator for security assessment. This procedure plays a vital role in risk assessment programs or while preparing a security plan for your organization. Practical Network Scanning starts with the concept of network scanning and how organizations can benefit from it. Then, going forward, we delve into the different scanning steps, such as service detection, firewall detection, TCP/IP port detection, and OS detection. We also implement these concepts using a few of the most prominent tools on the market, such as Nessus and Nmap. In the concluding chapters, we prepare a complete vulnerability assessment plan for your organization. By the end of this book, you will have hands-on experience in performing network scanning using different tools and in choosing the best tools for your system.
Table of Contents (19 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Internet security


These are the basic things you need to understand when you are working with online systems. When working with them day to day, we expose ourselves to risks.

Let's jump into the basic components of internet security.

Password

Since we own internet enabled devices, we are responsible for our own security. So, let's begin with our passwords. As users, we must choose a strong password. Alternatively, organizations should encourage users to choose one.

Password analysis shows that quite a common password used by users is 123456 and other similar, simple patterns. Most users choose the same password across multiple platforms. If a server or database is compromised by hackers, it would be easy to crack passwords such as this.

Few common web portals contain personal information. However, if an employee is required to create a username consisting of their first and last name or employee ID, and this is combined with a simple default password such as abcX123, then their information is easy to guess.

System upgrade and updates

The WannaCry ransomware attack was a worldwide cyberattack in May 2017 triggered by the WannaCry ransomware crypto worm. This attack targeted computers running the Microsoft Windows operating system by encrypting data and demanding ransom payments in the Bitcoin cryptocurrency. Such infection happens because people are running outdated software and attackers exploit this. This is not limited to PCs but also to mobile devices and other internet enabled devices.

Phishing

Phishing is a form of online fraud where you receive an email that looks similar to a trusted source. The message may ask you to validate, confirm, or update your account information by logging into fake websites. Targets are contacted via telephone, email, and text message, which are used to extract credit card details and passwords.

This is my own email box, which contains a message stating that I am supposed to get 13,17422 INR, and I need to update my details. While the attacker is using money as a temptation tool, it is important to think instead about your IT return. Is this type of mail really to be expected from the IT department? You can easily guess that this is not a genuine domain just by looking at the email header. Following the instructions of this message can consequently have disastrous consequences:

Beware of phishing phone calls

Attackers might call you on the phone and offer to solve your computer problems by selling you a software license or by obtaining your personal information in order to update your details in a backend system.

Once they've gained your trust, cybercriminals might ask for your username and password or ask you to go to a website to install software that will let them access your computer in order to fix it. Once you do this, your computer and your personal information is hijacked.

In the same way, a banking fraud can take place. This includes cybercriminals calling you and trying to persuade you to share your credit card and banking details.

Some signs of phishing phone calls include:

  • You have been specially selected for any offering
  • You have won money in a lottery
  • You have income tax refund
  • Someone asking about credit card CVV and other details to update a banking database

Phishing protection

Phishing attack protection requires steps to be taken by both users and enterprises. For users, awareness is the key. A spoofed message often contains some mistakes that expose its true identity. These can include spelling mistakes or changes to domain names, as seen in the earlier URL example. Users should also stop and think about why they're even receiving such an email or phone call.

You should report such emails to authorities so that appropriate actions can be taken.