Key factors.

• Open Ports.
• Insecure or non-updated software.
• Weak passwords policy.
• Attacks on administrator accounts.
• Lack of physical securities.

Open Ports.

Ports scanning is the first thing that any Attacker would do before attacking your servers. They could get an idea of which service can be compromised based upon open ports. There are multiple methods to scan and identify open ports Nmap is one of them.

# apt install nmap
# yum install nmap

Insecure or non-updated software

If you are not updating the server regularly, attackers can gain access via using exploits. Misconfigures services can be harmful too. Always make sure to keep Operating System updated. Multiple tools are available to test vulnerabilities. OpenVAS is one of the famous tool that can be installed on the server to scan vulnurabitiels.

Install OpenVAS

#apt install openvas
#yum install openvas

Start Service.

# openvas-start && openvas-setup

Login to get reports.

Weak passwords policy

Using a tool like hydra attackers can gain access if your system is set up with weak passwords and have unwanted ports open. Always use complicated passwords and keeping them changing from time to time can reduce the chances of attacks. Let’s take a look at how hydra can be used to target servers with weak passwords. create a list of usernames and passwords with all possible combinations (userlist.txt & passwd.txt are created in my scenario).

# apt install hydra

Run command.

# hydra -L /root/userlist.txt -p /root/passwd.txt -u 127.0.0.1 ssh

Attacks on administrator accounts

Remember, if an attacker can gain access to an administrator account. An attacker can gain access to other servers as well. Even after having to have good securities, the hackers were able to gain access. Always make sure not to share passwords with unauthorized persons.

Lack of physical securities

Proving multi-factor authentications, providing physical locks can save servers from unwanted access. Do not provide any direct physical access like monitors or keyboards. Block all USB or other serial ports that can be attached directly to servers. No media file sharing has to be with critical operational servers.

Conclusion.

Today, we have learned how an attacker can gain easy access to servers & how to avoid it. Scanning ports with Nmap, system’s health check with OpenVAS are part of security assessment. In the next article, we will understand other aspects of security.

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Programming the user’s account expiration.

Please note, this feature only works on Windows 10 Pro or Windows 10 Enterprise. First, we need to log in from an account with administrator privileges. Them, please type edit group policy in the search bar.

Once there, we will follow the following route: Local Computer Policy>Administrative Templates>System. Next, we locate in the right window: user profiles

Now, we have to double-click on Delete user profiles older than a specified number of days on system restart. Plainly, this feature is not configured by default, so we have to enable it to enjoy the characteristic.

In this window, we will see all the configurations related to the time of the accounts. The default time is 30 days, but it will depend on the administrator which amount of time will be assigned. Finally, we only have to press accept to execute the changes.

As can be seen, how to program the expiration of user accounts is a very interesting feature to control privacy on PCs. By controlling the expiration time of user accounts, we will be able to take care of the use of the hard disk. In addition to protecting our personal files from possible intrusions. All right, that’s it for the moment, please visit our Visual Studio article on Windows 10. Please join our channel in telegram

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Please keep in mind that when working with servers, security is a fundamental aspect. For this reason, there are several reasons for modifying the duration of passwords. For this reason, there are several reasons for modifying the duration of passwords. According to the type of use, it is convenient to establish passwords with security time. For example, to temporary users, test users or those who are practicing in the company.

Now, we have two options for modifying password expiration policies on Windows Server 2019. Group Policy: Apply for when the computer is included in a corporate domain with Windows Server Domain Controller. Local Security Policy: Applies when our group is not in a domain, but is in a workgroup or is managed locally. Here’s how to change a password or change the expiration date of a password within Windows Server 2019 step by step.

Changing password expiration through Local Security Policy on Windows Server 2019

Below we will detail the process for entering the password policy configuration.

Step 1. Open Local Group Policy Editor

First, we need to enter Group Policy Management by clicking Windows+R and typing gpedit.msc

Once there, we must follow the next route: Local Computer Policy>Computer Configuration>Windows Settings>Security Settings>Password Policy

Step 2. Editing password policies

The editor allows you to configure different aspects of the password:

Enforce password history. This security setting determines the number of unique new passwords that have to be associated with a user account before an old password can be reused. The value must be between 0 and 24 passwords.

Maximum password age. This security setting determines the period of time (in days) that a password can be used before the system requires the user to change it. You can set passwords to expire after a number of days between 1 and 999, or you can specify that passwords never expire by setting the number of days to 0.

Minimum password age. This security setting determines the period of time (in days) that a password must be used before the user can change it. You can set a value between 1 and 998 days, or you can allow changes immediately by setting the number of days to 0.

Minimum password length. This security setting determines the least number of characters that a password for a user account may contain. It can set a value of between 1 and 20 characters, or you can establish that no password is required by setting the number of characters to 0.

Password must meet complexity requirements. This security setting determines whether passwords must meet complexity requirements.

Password Requirements

If it enabled, the password must meet the following minimum requirements:

Not contain the user’s account name or parts of the user’s full name that exceed two consecutive characters
Be at least six characters in length
Contain characters from three of the following four categories:
English uppercase characters (A through Z)
English lowercase characters (a through z)
Base 10 digits (0 through 9)
Non-alphabetic characters (for example, !, $, #, %)

Store passwords using reversible encryption. This security setting determines whether the operating system stores passwords using reversible encryption. This policy provides support for applications that use protocols that require knowledge of the user’s password for authentication purposes.

Changing password expiration through Local Active Directory on Windows Server 2019

To access the domain password policy editor, we need to open the Server Manager. Next, click on the Active Directory Administrative Center tool.

In the next window, select the forest and then follow the following path: Domains>nameofdomain>Default Domain Policy. Where nameofdomain is the name of our domain, in my case telematic.local. Next, double click on Default Domain Policy to edit the values.

Once the window opens, follow this path: Default Domain Policy>Compuer Configuration>Policies>Windows Settings>Security Settings>Password policy

As we see we have the same options as in the local directives, the only difference is that if we open the local policies with our computer in a domain we cannot make any change in the directives. On the other hand, from a computer in a domain using this option if we will be able to make adjustments in the policies.

Changing or unlocking administrator password on Windows Server 2019

Sometimes it happens that we want to change the administrator password, or the account has been blocked. Sometimes it happens that we want to change the administrator password, or the account has been blocked. To do this, we must enter the Server Manager and select Active Directory Administrative Center.

Once there, all you have to do is select Reset Password, and enter the new password or unblock the account if it is locked.

As has been noted, the process for changing password policies is not that complicated. However, we must be careful when modifying these values, as it will affect the entry of users. In conclusion, Windows Server 2019 is a very friendly system and has wizards that facilitate the changes desired by the server administrator.

Well, this is all for now, before saying goodbye I would like to invite you to review our tutorial on installing Apache on Windows Server 2019.

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Basically, what this tool does is configure rules that can be for all users or a particular group. These rules can be imported or exported, applications can be locked according to the type of files, their scripts, and extensions. As we can see, it will give us total control over what can and cannot be installed. So let’s get on with it.

Configuring security rules in AppLocker

The first thing we have to do is enter in the Local Security Policy editor. With this intention, we need to press the key Windows + R, and in the run box, enter the term secpol.msc.

Once inside the window, follow this path: Security Settings>Application Control Policies>AppLocker

Click on AppLocker, to display the side menu, select Configure rule enforcement

This will open the properties box with the types of rules that can be configured. In this particular case we will select executables rules, but please note that you can choose the ones you want.

Then deploy AppLocker, right-click on Executable Rules and select the option Generate rules automatically.

A configurator will open and we will choose the users to whom the rule will be applied, the folder to analyze and the name of the rules.

In the next window choose the file filtering criteria: by type or by the path.

By pressing next, the rule creation process will start.

Finally, we will see a summary of the rules. Click on create to generate them. Moreover, a warning box will appear, just say yes and the procedure will be ready.

The following table will show the rules created.

Since the rules have been created, we can still edit them by double-clicking and selecting properties.

Configure the Application Identity service

Finally, the rules have been generated, now you only have to configure the Application Identity service. To the end that, just type PowerShell into the search bar to invoke a Windows PowerShell, double click on it to run as administrator and write next command:

 sc config appidsvc start=auto 

This is it! As you can see enable this tool, it is not very complicated to do, however, it is a great help for the security of our system. So this is it, for now, please don’t miss our Onwcloud Server tutorial on Windows 10

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