What is an Enumeration Attack? How they Work + Prevention Tips

Cybersecurity security issues are constant threats to businesses, individuals’ privacy, phishing scams, and intellectual property. If you or your company is safe yet, you are truly blessed.

Malicious actors are finding new ways to attack their target host daily. Enumeration attacks are one type of hacking or cybercrime. Have you ever been the victim of an enumeration attack? If yes, then do you know how they work?

Enumeration is the collection of your private data that you use when you’re working online or scrolling on the internet—personal data, configuration, IP address, passwords, DNS, etc.

If you want to know more about “enumeration attacks’, keep reading this article.

Let’s get started.

What is an Enumeration Attack?

Enumeration is a brute-force attack in which hackers develop an active connection to attack the target host. When the link is active, malicious actors can access your personal information such as passwords, configuration, log-in details, password reset page, IP address, etc.

When hackers access your system and build an active connection, they can now control your whole system and steal your data. Highly expert hackers can even change the configuration of the host’s system. It depends on the system’s installation, how easily an attacker can determine the target host’s sensitive information or data like a valid username.

How Does It Work?

Now that you know what enumeration is, the question may arise here: What do hackers do with the gathered information? Hackers use all the collected data to identify the weak points in the network to exploit the system.

Mostly the systems that aren’t paying attention to the latest techniques, such as firewalls, for securing their networks suffer the most. Enumeration is a severe issue that companies are facing each day.

Many businesses are investing tons of dollars in hiring employers with the knowledge of enumeration to prevent their system from enumeration attacks. Different username exists for employees and hackers can access or hack those valid usernames and leading to username enumeration attacks. There are other user enumeration attacks as well despite getting an error message of an invalid username.

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Types Of Enumeration Attacks

There are mainly eight types of enumeration attacks people experience.

  • Windows enumeration
  • NetBIOS enumeration
  • LDAP enumeration
  • SNMP enumeration
  • Linux/UNIX enumeration.
  • NTP enumeration
  • SMTP enumeration
  • DNS enumeration

1. Windows Enumeration

Windows enumeration is the primary type of enumeration attack. The malicious actor used a few techniques and tools to access your desktop workstation. Hacking your workstation means that the privacy of your documents is no longer protected. Now the hackers can access any of your files and modify them.

In a few cases, expert hackers can even change the configuration. The configuration changes mean that a malicious actor can now determine every action you do on your workstation.

Prevention Tip

You can prevent your desktop from being exploited by installing a windows firewall. The windows firewall is the primary application that you can use to avoid windows enumeration.

It works as a scanner, blocking any strange signal trying to develop a strong connection with your system.

2. NetBIOS Enumeration

NetBIOS stands for Network Basic Input Output System, which IBM and Sytek created. Initially, NetBIOS was an application to access LAN resources to a third party by client’s software.

Hackers use NetBIOS to gather passwords and later use them for modifying the host’s system. Malicious actors perform read/write operations on the hacked systems.


You can prevent it by minimizing the sharing of files and printers. Less use of the server can also fix it.

3. LDAP Enumeration

The word LDAP stands for Lightweight Directory Access Protocol. It is a type of directory store where all the information of a user’s record is stored.

When the hackers get access to LDAP, it reveals all the sensitive data, such as the username, password, and IP addresses.


You can prevent this malicious attack by executing SSL. You can also avoid this by enabling lockout.

4. SNMP Enumeration

SNMP stands for Simple Network Management Protocol. The hackers used it to gather information about the network details of the target host.

They gathered all the information, such as the devices their target host shared data with, the traffic statistics, etc.


You can prevent it by installing a firewall.

5. Linux/UNIX Enumeration

Hackers use this type of enumeration to target those networks whose operating system is Linux/UNIX.

It is similar to window enumeration with a slight change in operating systems. Hackers used this enumeration to gather sensitive information about the target host.


You can avoid this enumeration by modifying IP tables.

•	Linux/UNIX enumeration

6. NTP Enumeration

The hackers use NTP Enumeration to collect the data about the lists of hosts connected to the NTP server, IP address, names of the system, and OSs running on the system. A malicious actor can enumerate all this only by asking the NTP server.

7. SMTP Enumeration

SMTP provides three types of built-in commands.

VRFY, EXPN, RCP TO. These three server response is oppositely for valid and invalid users. With its help, you can differentiate between actual and fake users.

A malicious actor can legitimately link SMTP through telnet briefs and collect rundowns of the significant clients on the mainframe.

8. DNS Enumeration

DNS enumeration is the process of finding the documents of an objective organization.

A Hacker can gather data about a significant organization. For instance, DNS employees’ names, hostname, machine names, usernames, IP addresses, etc. If the username is compromised, it can refer as a username enumeration attack as well.

Also Check: Steps To Follow For SQL Security

How To Prevent Enumeration Attacks?

You can avoid all types of enumeration by following these steps:

  • MFA (Multi-Factor Authentication) is one of the effective methods to prevent enumeration attacks. When hackers try your login details, the server asks for the correct, authentic information. In this way, hackers can not get access to any server.
  • CAPTCHA is another way to protect your systems, but it is not as effective as MFA.
  • Train your staff about cybercrimes. Cybercriminals are experts; they can easily trap an untrained eye. Well-trained staff can identify hackers quickly.


Enumeration attacks are a type of cyber security. Many businesses, companies, and individuals are facing this issue each day. If you’re not paying attention to securing your system by utilizing modern techniques, you are lacking behind.

Hackers can steal your username, IP address, passwords, configuration by enumeration attacks. You can prevent these attacks by following the methods mentioned above. Still, having issues? Let us know in the comments below!

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