What is XSS and how many different categories are there?

Cross-site scripting (XSS) attacks are a type of web vulnerability that allows an attacker to inject malicious code into a website, which is then executed in the user’s browser. This can lead to a variety of malicious activities, including stealing sensitive user data, session hijacking, and even spreading malware.

There are several different types of XSS attacks that attackers can use to exploit web vulnerabilities, each with its own unique characteristics and potential for harm. In this article, we’ll closely examine some of the most common types of XSS attacks and how they work.

Reflected XSS

Reflected XSS attacks occur when an attacker injects malicious code into a URL or other input field that is then reflected back to the user’s browser as part of the website’s response. This type of attack is often used to steal sensitive user data, such as login credentials or personal information, by tricking users into entering their information into a fake login form.

Stored XSS

Stored XSS attacks occur when an attacker injects malicious code into a website’s database, which is then served to all users who access the affected page. This type of attack can be particularly dangerous because it can remain undetected for long periods of time, potentially allowing the attacker to collect large amounts of sensitive user data.

DOM-based XSS

DOM-based XSS attacks occur when an attacker injects malicious code into a website’s Document Object Model (DOM), which is then executed by the user’s browser. This type of attack can be particularly difficult to detect and prevent because it does not involve any interaction with the website’s server.

Blind XSS

Blind XSS attacks occur when an attacker can inject malicious code into a website, but the attack is not immediately visible to the user. This can happen when the attacker can inject the code into a hidden or obscure part of the website, or when the attack is triggered by a specific user action.


Self-XSS attacks occur when a user is tricked into injecting malicious code into a website, often by copying and pasting code from a malicious source. This type of attack can be particularly effective because it relies on the user’s actions to execute the malicious code.

Preventing XSS Attacks

There are several steps that website owners can take to prevent XSS attacks from occurring. These include:

Validating and sanitizing all user input to ensure it does not contain malicious code.

Implementing Content Security Policy (CSP) headers to prevent the execution of any code that does not originate from trusted sources.

Using HTTPS encryption to protect user data in transit.

Keep all website software and plugins up-to-date to ensure known vulnerabilities are patched as soon as possible.


XSS attacks are a serious threat to website security, and website owners should take steps to protect themselves and their users from these attacks. By understanding the different types of XSS attacks and implementing effective security measures, website owners can help to prevent these attacks from occurring and keep their users safe.


Is cybersecurity affordable for everyone?

Cybersecurity is essential for everyone, not just big corporations. While it is true that large organizations may have more resources and a greater need to protect their sensitive data, individuals also have important information that they need to protect. This can include personal or financial information, passwords, and other sensitive data that could be compromised if not properly secured.

Everyone must take responsibility for protecting themselves online, whether a large corporation or an individual. Some best practices are using strong passwords, Multifactor authentication (MFA), avoiding reusing the password on different platforms, being cautious when clicking on links or downloading files, and keeping software and devices up to date with the latest security patches.

We must protect the information and data because it has value, whether financial or social. In most cases, being proactive and protecting those assets is cheaper than the repercussions that we can have when that information is stolen.

What about the cost? The price to protect the organizations’ assets has grown exponentially in the last 25 years. Now it’s much more expensive to protect all the company’s information because the attacks are more sophisticated.

The bad actors are using more advanced tools, techniques, and technology. As a result, organizations need to acquire more security devices, applications, and solutions to be protected. In addition to all of this, there should be a commitment to educate and train all employees and end users.

Organizations, to maintain safe their information, need to get some of the below solutions:

Mail security
Intrusion detection system
Centralized logging
Security incident and event monitoring (SIEM).
Thread intelligence feed
Managed security service provider contract
Penetration tester
Machine Learning AI

With all of these resources, you need to increase the prices for your product or service to continue profitably. And the consumer will be paying for all them.

Even though those applications and solutions are the latest on the market, They are not something like set-and-forget kind of solution.

But wait a minute! For medium and large corporations. They have an assigned budget for all of these solutions., Nonetheless, where are all the others? A small. Business. Such as public schools. Nonprofits. Human service organizations. Smaller cities. And county governments. Community associations. Many of all these. Organizations they can’t afford. An infosec solution.

The challenge is how we can guarantee access to cybersecurity and make it available for everyone.

Thanks for reading.

Microsoft 365 network connectivity

Microsoft has released a new console to visualize the network performance between your corporate network and M365, this new feature will help the administrators to identify performance issues proactively.

This console has been released this month, and you can find it in the Health tab – Network connectivity.

The first time you have to join the network connectivity preview.

As part of the set up, you have to add a new location in your service, as the message indicated: “We need more data to generate network connectivity insights

To get started, turn on your location opt-in setting to automatically collect data from devices using Windows Location Services, go to your Locations list to add or upload location data, or have someone run the Microsoft 365 network connectivity test from your office locations.”

Click on the Locations tab, then click on Add Location.

Click on yes to allow Bing maps to get your location.

Input your network details in the new location, then click on save.

A confirmation will appear the location has been added.

Once you have the location(s) configurated, go to the right upper corner and select Network Connectivity Test.

The Microsoft 365 network connectivity test console will appear, read all the terms and click on run test.

As you can see below, there is information vital for review. Also you can run a .exe file to run the report on your own. 

Now you have one more tool to identify performance or network issues; this information will also provide metrics to the network team to adjust in the QoS or any other parameters in the networks.

I hope this information helps. Thanks for reading.

Microsoft Teams network assessment tool

If you are in the process of migrating from Skype for Business to Microsoft Teams for the first time, in that case, always is a best practice to execute the network assessment tool to identify any possible bottleneck in your internal network.

Sometimes, even when you have excellent network switches, the problem can be wireless clients’ access points.
When there is a branch office in the company, because they don’t have the same infrastructure as in the headquarter, this kind of tool will help you identify possible network problems before implementing Microsoft Teams.

Suppose you are already using Microsoft Teams, and you have bad quality in either voice or video. In that case, this tool is a good resource to identify what device or configuration is causing these failures.
When I say failures in your network, maybe it is just the quality of service configuration or adjustments that will allow using the same network. Still, with some improvements for the voice or video, in the same way, you will find some delays in your network or jitters, but again, if you don’t have this kind of tools, it will be hard to be 100% sure about what is going on in your internal network.

For all the messaging administrators that were using the same tool but for the Sky for business, this new version is exclusively for Microsoft Teams.

You can get that tool from this link Download Microsoft Teams Network Assessment Tool from Official Microsoft Download Center, download and install it on a computer.

Accept the license terms and click on Install
The progress bar will appears and also another window to install the program
Click on Next
Be careful of the path, you will need this information later
Click install and this is the last step.
Using a windows explorer, go to the installation path and double click on NetworkAssessmentTool.exe
You will see the tool validating the ports, IP’s to start the performance check.

Where you can see the results?

Open the file NetworkAssessmentTool.exe.config and you will find these configuration, you can modify if needed.

  <!-- Audio: 50000-50019
       Video: 50020-50039
       VBSS:  50040-50059 -->
  <add key="MinimumSourcePort" value="50000"/>
  <add key="MaximumSourcePort" value="50019"/>

  <!-- Duration of media flow for the quality checker, in seconds                               -->
  <!-- Note that Ctrl+C can be pressed at any time to stop the quality check                    -->
  <add key="MediaDuration" value="300"/>

  <!-- File name of where detailed service connectivity check results are stored                -->
  <!-- Directory: %appdata%\..\Local\Microsoft Teams Network Assessment Tool                    -->
  <add key="OutputFileName" value="service_connectivity_check_results.txt"/>

  <!-- File name of where quality check results are stored                                      -->
  <!-- Directory: %appdata%\..\Local\Microsoft Teams Network Assessment Tool                    -->
  <add key="ResultsFileName" value="quality_check_results.csv"/>

Thanks for reading, I hope it helps.

Tony Gonzalez

New feature in M365 to avoid email flow issues

I do remember in the past, when I started having issues with email been rejected, obviously we got a spike on tickets because this problem was affecting the whole company. After checking the NDR (Non-delivery report) and different workarounds, I realize that a certificate for exchange has expired.

There are different approaches to identify whether a certificate is about to expire; in this article https://tonygonzalez0379.com/2020/05/25/how-to-check-certificates-expiration-date-using-powershell, you can find how to use PowerShell to identify proactively if a certificate will expire in a period of time, in my case, I use 30 days in advance, so this script is being executed on weekends. You have plenty of time to renew the certificate before you significantly impact all end users.

Another common issue that affects the email flow is when a domain name is about to expire; sometimes, we get a domain name only for a year, and then when this domain expires, Exchange can’t continue delivering email to those users that contain the specific domain in the email address.

It is common that a user has different SMTP addresses, because those accounts need to receive emails using other domains, the same approach as the certificate, you could create a PowerShell script to validate the expiration date using The Who is information for those domains.

The good news is that Microsoft 365 now has a solution that can help the administrators to proactively identify if a certificate or domain name that is part of the registered domains in M365 is about to expire; this feature is new, and you will be able to see this notification in the insight area.

Also, the administrator will receive an email with this notification. I believe that this is great for all the messaging administrators in the company, because if you are not proactive, there is a high risk of having a problem like everyone can’t send or receive emails, and the business impact could be huge.

Below you can see an example of the domain expiration. You can find this in the exchange ministration console on Office 365, in the inside tab. In the same way, you will find the information about the certificates here. Nonetheless, it is better to have a solution like PowerShell, this is the old school, and pretty much all the Administrators are familiar with this process.

Here you can see the domains that will expire soon

Thanks for reading.

Tony Gonzalez

The new Microsoft 365 defender and security center

I was researching the ATP policies in Office 365 when I saw a message about the new features in Office 365 defender, as sometimes it happens when you start reading about a specific topic. You find different links to other various topics, and at the end, you finish reading about something different as you started. This is the case.

I would like to mention some benefits that Microsoft 365 security center and Microsoft 365 defender have to protect the information that is hosted in your M365 tenant.

The new M365 security center it’s similar to having a SIEM (Security Information and Event Management) because it provides detection, analytics, and response to different events in your organization.

In the Microsoft 365 Security Center, you can get alerts and notifications about incidents regarding security breaches.

Incident dashboard

For example, when a computer is detected sending unusual traffic, using a different port to connect applications, sites, or protocols, or if a mailbox has received malicious content like malware, virus, or phishing.

The security defender solution, besides detecting all of these attacks, also gives some playbooks to mitigate the incident and make sure that the security breach is mitigated.

In the situation where a user receives malware, the incident dashboard contains all the information regarding the computer infected, IP address, location, user details, mailboxes, and the level of the risk.

In our experience as messaging administrators, we know that regardless of all the technologies or systems that we have to identify and block malware, sometimes some emails pass through. Therefore, we need to purge the delivered emails.

Now, Office 365 can identify those emails and delete them from the mailbox, even when they have been delivered; this is known as ZAP (Zero-Hour Auto Purge). Once Office 365 identifies this problem, an alert is triggered, and the alert is correlated with an incident. Therefore, in the dashboard, we can see an investigation related to this event.

Office 365 security can act immediately without any human intervention.

NOTE: It’s important to mention that ZAP does not work in a standalone exchange Online Protection (EOP) environment that protects an On-prem exchange environment.

Report of all emails that were zapped

You can see how many emails have been Zapped, how many mailboxes have been affected, and the status of the purge; that means you can double-check that no one has that malicious email in the mailbox.

In the Microsoft 365 security center, we can see not only the email threats but their kind of alert and their status; meaning, whether that alert has been mitigated or it is in process, and you can drill down to see all details.

Part of the information that contains the alerts, you can see the user name, title, department, computer name, IP address, location, and much more data that is helpful to the administrator to review if the user was trying to log in on different computers that might be at risk.

Details about a user with a high risk score

As you can see from this figure, we could identify how risky a user is. In this example, the user is a high priority to investigate due to all the different events that her account had. Also, we can see all the various activities the user had in previous days or weeks.

Office 365 provides a score where we can quickly identify the top users where you need to take action because they can be compromised.

With the advanced hunting tool, you are able to query different system applications from Office 365 such as Defender for Office 365, Defender for EndPoint, Defender for Identity, Cloud App Security (CAS), ATP, EOP, and then use a query to get information from all this telemetry.

Advance hunting console

The output of these queries can give us more valuable information about an incident. For example, if there is a situation where the user account is compromised, we are talking that these credentials were trying to be stolen. Therefore we can identify if those credentials were used to try to access other computers.

As we know, some attackers start with a typical user and then, they move laterally until they find an admin user that can have access to any domain controller in the network.

After reviewing all the different capabilities that Microsoft Office 365 security provides, the solution can automatically detect anomalies, gathering formation from other Office 365 security products; as I stated before, now Office 365 has a kind of SIEM product where the security team is able to control all the different security incidents.

Alert when credentials were stolen or theft

Furthermore, we can see alerts regarding inbox forwarding rules to external email addresses, this is a common method the attackers use to extract information from users or companies, M365 defender creates an alert to notify the administrator that there is a suspicious rule in a mailbox, and then, a security administrator must take a look at this configuration and start an investigation.

I am stunned that Microsoft now has this kind of solution working towards having a cloud environment more secure.

 There is something that I always tell other skeptical engineers about migrating to the cloud, is that Office 365 and Microsoft Azure provide all the tools to make a secure environment.

 There are many different tools, policies, services, products, and solutions that we can implement to have a secure environment in the cloud. For example, ATP (Azure Threat Protection) policies where we can configure antimalware, Anti-Spam policies, safe attachments, safe links, data loss prevention (DLP), information protection (AIP), cloud application security (CAS), and much more security configurations!

This topic has much more to cover; this is only scratching the surface. I want to continue talking about this in other posts.

Thanks for reading

source: https://docs.microsoft.com/en-us/microsoft-365/security/mtp/microsoft-threat-protection?view=o365-worldwide


Thanks for reading, if this article was helpful or interesting, you can buy me either a coffee or beer.

Buy a coffee or beer to Tony, in that way he will continue working towards new article.


How to check certificates expiration date using PowerShell

A best practice is having an automate process to check the certificates expiration date, let’s say 60 days before their expiration, in that way proactively you can start the process to request a new certificates, besides of your company request process this article will help you identify those certificates with expiration date before 60 days.

First things first, lets identify where the certificates are located. You can use this cmdlet in PowerShell to see how many containers you have:

PS C:\> Get-ChildItem -Path Cert:\*

At this point we will focus on the LocalMachine because in your servers the most important are the machine certificates.

 PS C:\> Get-ChildItem -Path Cert:\localmachine

As you can see in the list, we have the folder My, here we will find the certificates that we use for different applications, for example SQL, Exchange, Web, Skype for business, etc.

PS C:\> Get-ChildItem -Path Cert:\localmachine\my

And we get the list of certificates

You could use the Format-List option to see all details for these certificates as follow

As you can see in detail, we have the parameter NotAfter, this is the most important for us at this moment because it indicates the expiration date, so let’s get this information for these certificates.

PS C:\> Get-ChildItem -Path Cert:\localmachine\my | select NotAfter

With this line we will see only the expiration date for all certificates

Now let’s filter for the next 60 days using the Get-Date functions as follow

PS C:\> Get-ChildItem -Path Cert:\localmachine\my | ?{$_.NotAfter -lt (get-date).AddDays(60)}

If you remember, I had three certificates but only two have already expired or will expire.

If you want to see all details you can add the Format-List option at the end after a pipe “|”

PS C:\> Get-ChildItem -Path Cert:\localmachine\my | ?{$_.NotAfter -lt (get-date).AddDays(60)} | fl

From here you could automate this process and run every week and send the report to your team, also you can play with the different options to get only the expiration day, subject, Thumbprint, etc.

Thanks for reading

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How to change the UPN on Windows domain

How to change the UPN on Windows domain.

When you are ready to migrate to o365 and realize that your domain is not routable because more than 10 years ago when the domain was created they used .local extension, now a lot of years later you have to fix it.

Another scenario is when the company A acquires Company B and its time to unify everything, you have to change UPN also.

In my opinion is more common the first scenario, the second one is an option though.

The process to complete this setting is as follow:

In your domain controller go to Active Directory Domains and Trusts

Right click on Active Directory domains and trusts and select properties

The UPN suffixes window will appear and here we can add an alternative Suffix as shown below:

Click on Add, then OK to register the alternative domain name.

Now we have another UPN suffix in our domain, we can change this domain name either to specific users or the whole domain users.

In this case lets change to a specific user. To do so, open Active Directory Users and Computers and find a user to change the UPN.

Right click and select properties, then click on Account tab and click on the domain name

As you can see on the figure, now we have available the new domain name, then select the new UPN suffix and click on OK.

Lets validate the change using PowerShell:

As you can see on the UPN attribute, we have now the correct domain name.

So, if you need to change the same for all users in your domain you can do in different ways.

Here you have an script to do so.

# How to change the UPN by Tony Gonzalez

#Lets create a variable to assign the users to affect.

#In case you can modify only few users, you can assign those users to this variable

$Users = Get-ADUser -Properties * -Filter * -SearchBase “OU=UK,DC=TonySolutions,DC=com”

#$Users = Get-ADUser -Properties * -Filter *

Write-Host “The total of users to change the UPN are: $($Users.Count)” -ForegroundColor Yellow

Write-Host “Are you sure to continue? (Y/N)” -ForegroundColor Yellow

$Continue = Read-Host

if($Continue -like ‘y’)


    foreach($User in $Users)


        $NewUserUPN =  $User.UserPrincipalName.Replace(“TonySolutions.com”,”TonyGonzalez0379.com”)

        #Notification about the user we are working on

        $Name = $User.SamAccountName

        Write-Host “Working with $($Name)”

        #Applying the change

        Set-ADUser $Name -UserPrincipalName $NewUserUPN

        #Validating the change

        $Sam = $User.SamAccountName

        Get-ADUser $Sam -Properties UserPrincipalName





 Write-Host “No changes made to the $($Users.Count) Users” -ForegroundColor Green


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How to configure a NAT switch on Hyper-V

Everyone has used a lab environment either to test new technologies or to have a safe environment to test scripts or any other configuration, for some hypervisors like VMWare you need to have licenses to use networking devices like switches.

On Oracle VirtualBox you need to have advance networking and Linux skills to create some Virtual machines using Linux as Operating system and then create the routers and switches.

After you have this Linux computers and configure the Switch or router role then configure your internal network.

Another option is creating a Windows server with the NAT role installed, but again we need to create another computer that needs storage on the Hard drive, memory and CPU from the host, sometimes we don’t have enough resources for this.

Fortunately, we have another free option using Hyper-V and creating a NAT switch, in my experience using this option my environment is faster than using another computer as NAT server.

NOTE: If you need help to install the Hyper-V feature on Windows 10 follow this process How to configure Hyper-V on Windows 10

This is my virtual environment with three virtual computers connected to a default switch:

The complete design is as follow:

That means the host cannot provide internet access to the Virtual machines because we are assigning a different IP range.

In order to solve this problem lets create a new virtual switch and configure it as NAT switch.

To complete the configuration open PowerShell ISE as administrator on the host computer.

We are creating the switch as shown below:

The next sped is create the virtual interface for this network

And finally, we need to create the network

Make sure you connect the network interface of the Virtual machines (In my case VM1, VM2, VM3 and VM4) to the NAT Switch, immediately these computers will have internet access.

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How to enable Hyper-V on Windows 10

Now we can use Hyper-V as hypervisor on Widows 10 and its very easy enable this feature. We have different ways to do this, the first its via GUI and the second, of course using PowerShell.

To enable this feature using GUI lets follow these steps:

  1. From Run menu type control to open control panel

In Control panel go to programs and features

then Turn windows feature on or off

Check Hyper-V and click on Ok

Click on restart and the Hyper-V feature has been added.

Now lets add the same windows feature but using PowerShell, you need to open PowerShell as administrator, then run this line:

PS C:\> Get-WindowsOptionalFeature -Online -FeatureName “*Hyper*” | Enable-WindowsOptionalFeature -Online

And confirm to restart your computer, as shown below:

Thanks for reading and I hope this helps.