All posts by moh10ly

Script to delete all DPM 2019 recovery points

The Story

I have DPM server deployed and I got couple of Exchange Servers and with about 2 TB of data.

I scheduled DPM to backup Exchange four days a week, then I used the deduplication command to make a use of non used space. however that didn’t give me enough space.

As an alternative I planned to delete the recovery points each start of every month.

The script provided by Microsoft’s article about DPM here doesn’t really provide anyhow on how to delete a protection group with multiple recovery points.

After spending lots of digging I tried to create my own script.

Caution:

Please use this script with caution as it delete every Protection Group’s Recovery Points.

If you need custom script to delete recovery points for a specific date please don’t hesitate to send me an email.

Script:

$pgList = Get-ProtectionGroup $env:COMPUTERNAME

ForEach($pg in $pgList) {

  $dsList = Get-Datasource -ProtectionGroup $pg

  ForEach($ds in $dsList) {

    $RP = Get-DPMRecoveryPoint -Datasource $ds; $RP
        foreach ($P in $RP){
           Remove-DPMRecoveryPoint -RecoveryPoint $p -Confirm:$false -forcedeletion
  } }

}

If you think this script has a mistake or can be improved please leave a comment or drop me an email.

References:

Testing Office 365 SMTP relay

In order to test Office 365 SMTP relay you will have to create a user with an Exchange online license. After the email is activated for this user you can test this user for relay with the following powershell.

First connect to Microsoft Online service with this user that you’ll be using for relaying.

$msolcred = Get-Credential

Next edit the following powershell with the user’s e-mail and the recipient’s too

Send-MailMessage -From Office365User@Domain.com -To info@moh10ly.com -Subject “Test Email” -Body “Test SMTP Relay Service” -SmtpServer smtp.office365.com -Credential $msolcred -UseSsl -Port 587

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https://technet.microsoft.com/en-us/library/dn554323(v=exchg.150).aspx

This test is known as Client SMTP submission you can also use a different method for multiple devices where you can configure them all to point to a single server (IIS) in a method known as IIS for relay with Office 365 however, all the methods what involve office 365 (Only) for relay will require a user with Exchange online license assigned to it.

https://technet.microsoft.com/en-us/library/dn592151%28v=exchg.150%29.aspx

Note:

The use of this command is not recommended for security reasons in particular for not supporting the modern protocols. use it on your own risk and make sure the user assigned to this service has no privilege’s or not any Office 365 feature admin or power user.

Securing and Testing your Exchange Server with Pfsense HAProxy

– Using the CVE-2021-26855 Payload

After the recent vulnerabilities that hit Exchange Servers On-premises I found sometime to install KaliLinux and try to check what kind of information would I get from the patched servers.

I downloaded the payloads and tried to run it against couple of clients that I have patched the servers for luckily no authentication was made.

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– Using Nikto scanner

By using Nikto command from Kali Linux I could see what  Information could Exchange expose using

The command line is nikto –h mail.domain.com and the result of the scan would be exposing the Server’s name, local IP address, OWA Version,  ASP Net platform and version.

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Since I have my Exchange Server published via HAProxy 1.8 on Pfsense then I had to tweak HAProxy to strengthen the ciphers, make sure that HSTS is in place and deny the headers that expose the server’s sensitive information.

The result is pretty good as it also has affected the server’s score on ssllabs.com

Prior to the tweaking  my owa scan result on SSL Labs would get an A

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– Pfsense’s HAProxy Settings before

Before upgrading Pfsense to the latest version HAProxy was on 1.6 and the ssl/tls settings were also different as they were setup through the Advanced SSL options on the frontend however, now this is no longer supported and you’ll have to remove that and set it up on the “Global Advanced pass thru” in the General setting page.

ssl-default-bind-options ssl-min-ver TLSv1.2

tune.ssl.default-dh-param 2048

ssl-default-bind-ciphers ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!3DES:!MD5:!PSK

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Right after you save this, you will still need to change another settings on the Frontend to protect your server’s information from being exposed.

In the HAProxy settings Go to Frontend > Scroll down all the way to “Advanced pass thru” and paste the following:

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# Remove headers that expose security-sensitive information.

rspadd X-Frame-Options:\ SAMEORIGIN
rspidel X-FeServer:.*$
rspidel ^Server:.*$
rspidel ^X-Powered-By:.*$
rspidel ^X-AspNet-Version:.*$
rspidel X-WsSecurity-Enabled:.*$
rspidel X-WsSecurity-For:.*$
rspidel X-OAuth-Enabled:.*$
rspadd X-Xss-Protection:\ 1;\ mode=block
rspadd Strict-Transport-Security:\ max-age=31536000;includeSubDomains;preload
rspadd Referrer-Policy:\ no-referrer-when-downgrade
rspidel Request-Id:.*$
rspidel X-RequestId:.*$
rspadd X-Content-Type-Options:\ nosniff


In the below result, I have got almost everything protected well except for the OWA version which can be a bit problematic. In the next article I am going to try and mitigate this so the server can be protected in the expected manner.

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– The Result

Now the server is showing a totally different result and the Nikto scan is not revealing anything anymore.

SSLabs

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https://securityheaders.com/

The reason why I got B on security headers is due to the fact that Content-Security-Policy header will malfunction the ECP and OWA Login pages. Permission Policy is new feature and I couldn’t find anything about it on HAProxy.

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I hope this helps

Refences:

https://securityheaders.com/

https://www.ssllabs.com/

https://www.haproxy.com/documentation/aloha/12-0/traffic-management/lb-layer7/http-rewrite/

https://www.net7.be/blog/article/xss_csrf_http_security.html

Exchange Server backdoor investigation tools

The Story

After the disastrous exploit that was found in Microsoft Exchange Servers lots of corporations started immediately patching their servers with the latest Cumulative update and Security patches. The question is would those patches be enough if the server is already hacked or have a backdoor installed already?

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What are those 0-day exploits ?

The vulnerabilities recently being exploited were CVE-2021-26855, CVE-2021-26857, CVE-2021-26858, and CVE-2021-27065 which are part of alleged “State-sponsored Chinese group” according to Microsoft.

Let’s get into details of those exploits one by one:

CVE-2021-26855 is a server-side request forgery (SSRF) vulnerability in Exchange which allowed the attacker to send arbitrary HTTP requests and authenticate as the Exchange server.

CVE-2021-26857 is an insecure deserialization vulnerability in the Unified Messaging service. Insecure deserialization is where untrusted user-controllable data is deserialized by a program. Exploiting this vulnerability gave HAFNIUM the ability to run code as SYSTEM on the Exchange server. This requires administrator permission or another vulnerability to exploit.

CVE-2021-26858 is a post-authentication arbitrary file write vulnerability in Exchange. If HAFNIUM could authenticate with the Exchange server then they could use this vulnerability to write a file to any path on the server. They could authenticate by exploiting the CVE-2021-26855 SSRF vulnerability or by compromising a legitimate admin’s credentials.

CVE-2021-27065 is a post-authentication arbitrary file write vulnerability in Exchange. If HAFNIUM could authenticate with the Exchange server then they could use this vulnerability to write a file to any path on the server. They could authenticate by exploiting the CVE-2021-26855 SSRF vulnerability or by compromising a legitimate admin’s credentials.

How to proceed ?

Microsoft released couple of tools that could diagnose your servers and check if you already have been infected with a backdoor or any of these nasty malware and also remove those infected files or clean them and ask you for a restart if it’s required.

Tools:

  1. MSERT (Microsoft Safety Scanner) detects web shells, Download here .
  2. Health Checker (Scans your server for any vulnerabilities and whether you have updated Server CU and installed patches). Download here
  3. Exchange WebShell Detection (A simple PowerShell that is fast and checks if your IIS or Exchange directory has been exploited). Download here
  4. Scan your exchange server for proxy logon:
    https://github.com/microsoft/CSS-Exchange/tree/main/Security
  5. Microsoft very recently created a mitigation tool for Exchange on-premises that would rewrite url for the infected servers and recover the files that were changed. You can download the tools from this github link.

    https://github.com/microsoft/CSS-Exchange/tree/main/Security

    Copy the Test-ProxyLogon code into Notepad
    Save As “Test-ProxyLogon.ps1” with the quotes in your C:\Temp folder
    Run in Exchange Management Shell: .\Test-ProxyLogon.ps1 -OutPath C:\Temp

Scan Result

Scan result should show you the following if your servers has been exploited already.

This will remove the infections and asks for a restart.

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References:

https://www.microsoft.com/security/blog/2021/03/02/hafnium-targeting-exchange-servers/

https://www.bleepingcomputer.com/news/security/microsoft-exchange-updates-can-install-without-fixing-vulnerabilities/

https://github.com/dpaulson45/HealthChecker?mkt_tok=eyJpIjoiTURRMk5HRTFaV1V6TkRrMCIsInQiOiJcL3ZOTkRUVzdXdkJmTm5ibUIzTExKTDVxXC9ObFAxTmZLanFRZ0xpcDkxMW5raVE0dlRwV2FhVFFmWlVUVFZaZUdFM1NlcEFNTEZ6dTh5aWlqcVBpV3J2R2IxbGJxMmNUZ1ppYjJyZklnMjZFZngrM2tBUnNsM1JKcHJsSU1ib3BTIn0%3D#download

Zammad throws error csrf token verification failed! Apache 2.4.41 Ubuntu 20.4

Symptoms:

Right after a fresh installation of Zammad you implement Let’s Encrypt and you are unable to login to your Zammad portal due to the following error.

CSRF token verification failed!

Cause:

When you install Zammad, it’ll automatically create a zammad.conf file under the path /etc/apache2/sites-enabled.

Until this moment your web page should be functioning normal, the problem starts when you implement the Let’s Encrypt certificate which creates another .conf file that would corrupt the web server and cause the error you’re having.

Solution:

To solve this problem simply, change the extension of the zammad-le-ssl.conf file into something else other than .conf and restart apache or nginx.

Solution 2:

You need to uncomment the “ServerTokens Prod” part in your configuration file if the solution 1 doesn’t work.

Solution 3:

Beneath the SSO Setup you need to make sure to change the RequestHeader set X_FORWARDED_PROTO ‘http’ to https as in the below line.

After you apply all those, you need to restart both apache and zammad services.

Here’s a working configuration of Zammad


# security - prevent information disclosure about server version
ServerTokens Prod

<VirtualHost *:80>
    ServerName support.cloud-net.tech
    Redirect permanent / https://support.cloud-net.tech
</VirtualHost>

<VirtualHost *:443>
    SSLEngine on
    SSLProtocol all -SSLv2 -SSLv3
    SSLCipherSuite EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH

    SSLCertificateFile /etc/letsencrypt/live/support.cloud-net.tech/fullchain.pem
    SSLCertificateKeyFile /etc/letsencrypt/live/support.cloud-net.tech/privkey.pem
    SSLOpenSSLConfCmd DHParameters /etc/ssl/dhparam.pem

    ## don't loose time with IP address lookups
    HostnameLookups Off

    ## needed for named virtual hosts
    UseCanonicalName Off

    ## configures the footer on server-generated documents
    ServerSignature Off

    ProxyRequests Off
    ProxyPreserveHost On

    <Proxy 127.0.0.1:3000>
      Require local
    </Proxy>

    ProxyPass /assets !
    ProxyPass /favicon.ico !
    ProxyPass /apple-touch-icon.png !
    ProxyPass /robots.txt !
    ProxyPass /ws ws://127.0.0.1:6042/
    ProxyPass / http://127.0.0.1:3000/

    # change this line in an SSO setup
    RequestHeader unset X-Forwarded-User
    RequestHeader set X_FORWARDED_PROTO 'https'

    # Use settings below if proxying does not work and you receive HTTP-Errror 404
    # if you use the settings below, make sure to comment out the above two options
    # This may not apply to all systems, applies to openSuse
    #ProxyPass /ws ws://127.0.0.1:6042/ "retry=1 acque=3000 timeout=600 keepalive=On"
    #ProxyPass / http://127.0.0.1:3000/ "retry=1 acque=3000 timeout=600 keepalive=On"

    DocumentRoot "/opt/zammad/public"

    <Directory />
        Options FollowSymLinks
        AllowOverride None
    </Directory>

    <Directory "/opt/zammad/public">
        Options FollowSymLinks
              Require all granted
    </Directory>
</VirtualHost>
# security - prevent information disclosure about server version
ServerTokens Prod

<VirtualHost *:80>
    ServerName support.cloud-net.tech
    Redirect permanent / https://support.cloud-net.tech
</VirtualHost>

<VirtualHost *:443>
    SSLEngine on
    SSLProtocol all -SSLv2 -SSLv3
    SSLCipherSuite EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH

    SSLCertificateFile /etc/letsencrypt/live/support.cloud-net.tech/fullchain.pem
    SSLCertificateKeyFile /etc/letsencrypt/live/support.cloud-net.tech/privkey.pem
    SSLOpenSSLConfCmd DHParameters /etc/ssl/dhparam.pem

    ## don't loose time with IP address lookups
    HostnameLookups Off

    ## needed for named virtual hosts
    UseCanonicalName Off

    ## configures the footer on server-generated documents
    ServerSignature Off

    ProxyRequests Off
    ProxyPreserveHost On

    <Proxy 127.0.0.1:3000>
      Require local
    </Proxy>

    ProxyPass /assets !
    ProxyPass /favicon.ico !
    ProxyPass /apple-touch-icon.png !
    ProxyPass /robots.txt !
    ProxyPass /ws ws://127.0.0.1:6042/
    ProxyPass / http://127.0.0.1:3000/

    # change this line in an SSO setup
    RequestHeader unset X-Forwarded-User
    RequestHeader set X_FORWARDED_PROTO 'https'

    # Use settings below if proxying does not work and you receive HTTP-Errror 404
    # if you use the settings below, make sure to comment out the above two options
    # This may not apply to all systems, applies to openSuse
    #ProxyPass /ws ws://127.0.0.1:6042/ "retry=1 acque=3000 timeout=600 keepalive=On"
    #ProxyPass / http://127.0.0.1:3000/ "retry=1 acque=3000 timeout=600 keepalive=On"

    DocumentRoot "/opt/zammad/public"

    <Directory />
        Options FollowSymLinks
        AllowOverride None
    </Directory>

    <Directory "/opt/zammad/public">
        Options FollowSymLinks
              Require all granted
    </Directory>
</VirtualHost>
# security - prevent information disclosure about server version
ServerTokens Prod

<VirtualHost *:80>
    ServerName support.cloud-net.tech
    Redirect permanent / https://support.cloud-net.tech
</VirtualHost>

<VirtualHost *:443>
    SSLEngine on
    SSLProtocol all -SSLv2 -SSLv3
    SSLCipherSuite EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH

    SSLCertificateFile /etc/letsencrypt/live/support.cloud-net.tech/fullchain.pem
    SSLCertificateKeyFile /etc/letsencrypt/live/support.cloud-net.tech/privkey.pem
    SSLOpenSSLConfCmd DHParameters /etc/ssl/dhparam.pem

    ## don't loose time with IP address lookups
    HostnameLookups Off

    ## needed for named virtual hosts
    UseCanonicalName Off

    ## configures the footer on server-generated documents
    ServerSignature Off

    ProxyRequests Off
    ProxyPreserveHost On

    <Proxy 127.0.0.1:3000>
      Require local
    </Proxy>

    ProxyPass /assets !
    ProxyPass /favicon.ico !
    ProxyPass /apple-touch-icon.png !
    ProxyPass /robots.txt !
    ProxyPass /ws ws://127.0.0.1:6042/
    ProxyPass / http://127.0.0.1:3000/

    # change this line in an SSO setup
    RequestHeader unset X-Forwarded-User
    RequestHeader set X_FORWARDED_PROTO 'https'

    # Use settings below if proxying does not work and you receive HTTP-Errror 404
    # if you use the settings below, make sure to comment out the above two options
    # This may not apply to all systems, applies to openSuse
    #ProxyPass /ws ws://127.0.0.1:6042/ "retry=1 acque=3000 timeout=600 keepalive=On"
    #ProxyPass / http://127.0.0.1:3000/ "retry=1 acque=3000 timeout=600 keepalive=On"

    DocumentRoot "/opt/zammad/public"

    <Directory />
        Options FollowSymLinks
        AllowOverride None
    </Directory>

    <Directory "/opt/zammad/public">
        Options FollowSymLinks
              Require all granted
    </Directory>
</VirtualHost>

Hope this helps

Secure Zammad with LetsEncrypt Certıfıcate on Ubuntu 20.4 Apache

The Story

after installing Zammad ticketing system I tried to implement Let’sEncrypt certificate to secure the system but there was nothing available on the internet except an old article about implementing this on Ubuntu 16 with Nginx (see article here).

In my case I was using apache and no Nginx in place, and after installing Zammad it was using pretty fine on Http but needed to redirect http to HTTPS after implementing the certificate.

Zammad: Intuitive Service Desk with connection to i-doit | i-doit

Solution:

I first Installed Certbot for apache and then I took a backup of all my Zammad configuration and made sure not to alter the default Zammad directory.

So I created a dummy folder called /var/www/support and a file called /var/www/support/index.html within that folder and provided them the appropriate permissions.

sudo apt install certbot python3-certbot-apache

 sudo mkdir /var/www/support

sudo chown -R $USER:$USER /var/www/support

sudo chmod -R 755 /var/www/support

sudo nano /var/www/support/index.html


Edit the index.html file with the following to make sure that it works

<html>
             <head>
                         <title>Welcome to Your_domain!</title>
             </head>
             <body>
                       <h1>Success! The your_domain virtual host is working!</h1>
           </body>
</html>

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Edit Zammad’s Default Config File

Please make sure you take a move the original copy of Zammad file to another location using the following command

sudo mv /etc/apache2/sites-enabled/zammad.conf /etc/apache2/sites-enabled/zammad.bak

Then we’ll replace the file with this configuration but since we moved the original file to .bak then we’ll have to recreate it with our intended configuration.

Edit a new zammad.conf file and copy the configuration below

sudo vi /etc/apache2/sites-enabled/zammad.conf

Configuration starts below this:

#

# this is the apache config for zammad

#

# security – prevent information disclosure about server version

#ServerTokens Prod

<VirtualHost *:8080> # I changed the default port of Zammad to 8080 to allow Letsencrypt to connect on 80 and create the certificate

# replace ‘localhost’ with your fqdn if you want to use zammad from remote

ServerName localhost:8080

## don’t loose time with IP address lookups

HostnameLookups Off

## needed for named virtual hosts

UseCanonicalName Off

## configures the footer on server-generated documents

ServerSignature Off

ProxyRequests Off

ProxyPreserveHost On

<Proxy 127.0.0.1:3000>

Require local

</Proxy>

ProxyPass /assets !

ProxyPass /favicon.ico !

ProxyPass /apple-touch-icon.png !

ProxyPass /robots.txt !

ProxyPass /ws ws://127.0.0.1:6042/

ProxyPass / http://127.0.0.1:3000/

— INSERT — 10,38 Top

DocumentRoot “/opt/zammad/public”

<Directory />

Options FollowSymLinks

AllowOverride None

</Directory>

<Directory “/opt/zammad/public”>

Options FollowSymLinks

Require all granted

</Directory>

</VirtualHost>

<VirtualHost *:80>

ServerName support.cloud-net.tech

DocumentRoot /var/www/support

ErrorLog ${APACHE_LOG_DIR}/error.log

CustomLog ${APACHE_LOG_DIR}/access.log combined

</VirtualHost>

– ————————-

In the above configuration we did two things:

1- Replacing the original Zammad listening port instead of 80 to 8080

2- Created a new virtual host that points to our dummy folder /var/www/support

Save the file and exit from vi

Make sure you restart Apache after this

sudo systemctl restart apache2

Enable the new site configuration

sudo a2ensite zammad.conf

Lets create the certificate

In the below commands , the first one will drive you through the process of getting the certificate.

The second checks the status of the configuration of the auto renewal script certbot and third command tests the renewal of the certificate.

1- sudo certbot –apache

2- sudo systemctl status certbot.timer

3- sudo certbot renew –dry-run

As you can see in the below screenshot the command also asks you if you’d like to redirect all http traffic to HTTPS. You should want to say Y to that.

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When you accept creating Redirection rule from HTTP to HTTPs the main Zammad config will get that configuration which wont work in that case because we already changed the default zammad port to 8080.

So you’ll need to get into that zammad.conf that you created again and enter the redirection portion

image

# this is the apache config for zammad
#


# security – prevent information disclosure about server version
#ServerTokens Prod


<VirtualHost *:8080>
     # replace ‘localhost’ with your fqdn if you want to use zammad from remote
     ServerName support.cloud-net.tech:8080


    ## don’t loose time with IP address lookups
     HostnameLookups Off


    ## needed for named virtual hosts
     UseCanonicalName Off


    ## configures the footer on server-generated documents
     ServerSignature Off


    ProxyRequests Off
     ProxyPreserveHost On


    <Proxy 127.0.0.1:3000>
         Require local
     </Proxy>


    ProxyPass /assets !
     ProxyPass /favicon.ico !
     ProxyPass /apple-touch-icon.png !
     ProxyPass /robots.txt !
     ProxyPass /ws ws://127.0.0.1:6042/
     ProxyPass /
http://127.0.0.1:3000/


    # change this line in an SSO setup
     RequestHeader unset X-Forwarded-User


     DocumentRoot “/opt/zammad/public”


    <Directory />
         Options FollowSymLinks
         AllowOverride None
     </Directory>


    <Directory “/opt/zammad/public”>
         Options FollowSymLinks
         Require all granted
     </Directory>


RewriteEngine on
RewriteCond %{SERVER_NAME} =support.cloud-net.tech
RewriteRule ^
https://%{SERVER_NAME}%{REQUEST_URI} [END,NE,R=permanent]

<VirtualHost *:80>
     ServerName support.cloud-net.tech
RewriteEngine on
RewriteCond %{SERVER_NAME} =support.cloud-net.tech
RewriteRule ^
https://%{SERVER_NAME}%{REQUEST_URI} [END,NE,R=permanent]
</VirtualHost>

image

Note:

You need to make sure that you have enabled port 443 on your Firewall and changed the main protocol of Zammad to HTTPs

To do so you’ll need to get into the Zammad portal > Settings > System > Http Type and change that to HTTPS.

image

That’s it, my example here worked as expected and now my traffic is automatically getting redirected to https.

image

Hope this helps anyone looking for such configuration.

Please consider donating to this Bitcoin account if you like this article or website.

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Secure Your DNS Traffic with the outside world

DoH in Microsoft Windows OS

Until this moment Microsoft Windows OS doesn’t support DNS over HTTPS, The feature will most likely be implemented in future builds but no body knows when is that however, You can still take a peak into the feature which is in preview mode/

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Benefit of using DoH on an OS level

The benefit of using DoH on an Operating System level would provide more certainty that your DNS queries leave your computer without being read by any other party even if that is your ISP.

A simple DNS nslookup query using Wireshark on your computer would show you how serious this topic is. After installing Wireshark you’ll be able to see that all of your dns queries are in clear text and can be read by anyone until it gets to the destination website/server.

Demonstration of DNS lookup without DoH

After installing Wireshark, I fire up Powershell or CMD and try to nslookup google.com and it’ll show what I just queried for.

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So how to make sure that your DNS queries don’t leave your computer in clear text format? and since Microsoft OS is not DoH ready yet what can you do?

In my case, I am already using encrypted DNS on firewall level as I have Pfsense acting as a router and it already supports DoH but still not pretty satisfied :).

DNSCrypt as a solution

Since the foundation of DoH I have been looking for a solution that would work on Microsoft Windows OS and luckily someone already created this great project called Simple DNSCrypt which not just enables the encryption of DNS queries on your OS but also enables this to work as a service.

No alt text provided for this image

Installing DNSCrypt would create a Windows based Service which would start automatically when your OS boots and logs into Windows.

The service is called DNSCrypt Client Proxy

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DNSCrypt has a simple interface, You can pick up the DNS Server where to forward queries to and it works with proof.

Right after the installation of this tiny app, launch it as an administrator and configure it as in the below screenshot. You can choose to install the service or not.

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Right after you enable it (By clicking on your Network Card box) that will start protecting your DNS queries. Let’s go ahead with a little demo

I am going to start Wireshark after enabling DnsCrypt and do a google dns lookup , As you can see below on wireshark it’s not returning any dns queries.

No alt text provided for this image

When you install Simple DNSCrypt it changes your Preferred DNS configuration to localhost so that all queries is passed through the app in DNS over HTTPS which doesn’t allow even Wireshark to see it as DNS.

So that makes it pretty secure and not even your firewall will see it.

If you have any question please don’t hesitate to ask me

Official DNScrypt website https://simplednscrypt.org/

Support the project founder https://github.com/bitbeans/SimpleDnsCrypt

Mimecast trust cert hacked in Microsoft supply chain

image

The Threatpost.com and other cyber security news published articles claiming that A Mimecast-issued certificate used to authenticate some of the company’s products to Microsoft 365 Exchange Web Services has been “compromised by a sophisticated threat actor,” the company has announced.

Office 365 Products and Services Explained

Mimecast provides email security services that customers can apply to their Microsoft 365 accounts by establishing a connection to Mimecast’s servers. The certificate in question is used to verify and authenticate those connections made to Mimecast’s Sync and Recover (backups for mailbox folder structure, calendar content and contacts from Exchange On-Premises or Microsoft 365 mailboxes), Continuity Monitor (looks for disruptions in email traffic) and Internal Email Protect (IEP) (inspects internally generated emails for malicious links, attachments or for sensitive content).

A compromise means that cyberattackers could take over the connection, though which inbound and outbound mail flows, researchers said. It would be possible to intercept that traffic, or possibly to infiltrate customers’ Microsoft 365 Exchange Web Services and steal information.

Reference:

https://threatpost.com/mimecast-certificate-microsoft-supply-chain-attack/162965/

https://www.crn.com/news/security/hackers-compromise-mimecast-certificate-for-microsoft-authentication

3- Migrate Users from Skype for Business 2015 to Teams

Hybrid Integration

In my last post about Skype for Business / Office 365 Skype for Business Online/Teams migration article I discussed the steps of how to create a hybrid environment between Skype for Business on-premises and went through the troubleshooting of each issue I have been through. In this article I am going to discuss the migration of users from on-premises to the cloud through UI and PowerShell.

Migrating users

This article will assume that you are planning to migrate users from Skype for Business Frontend 2015 Server and that you already have a hybrid configuration in place. If so then you’re going to fulfill the following prerequisites:

To check the currently installed PowerShell run the following cmdlet

$PSVersionTable

clip_image001

After you Download and install PowerShell 5.1 you might need to restart the server. In which case the PowerShell will show that it is updated to the required version.

image

After Installing the Skype Online Connector Module, We will be able to connect right after launching PowerShell

To do so type:

Import-Module SkypeOnlineConnector

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Connecting to Office 365 (Teams Online or Skype for Business Online)

The process of connecting to Office 365 Online PowerShell sounds easy but with MFA enforced in your environment you’ll have a nightmare mix of errors when you try so.

I have came through a lot of errors trying to force the use of PowerShell with MFA user authentication but eventually came to realize that Microsoft still does not support MFA for some cmdlets like Move-CsUser for instance.

So In short, to connect you’ll need to have a global or Teams admin user with MFA disabled to do so.

To create a new Skype Online Session enter:

– Make sure you start the regular PowerShell as admin and not Skype for Business Management Shell.

If you run these commands from SfB Management Shell you’ll get an error

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So first, We will import the Skype Online connector Module

Import-Module SkypeOnlineConnector

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Then get the OverRidePowershell URI using the command:

Get-CsOnlinePowerShellEndPoint

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Next, We will connect and authenticate to our tenant using the following cmdlet

$sfbsess = New-CsOnlineSession -Username User@domain.onmicrosoft.com -OverRidePowerShellUri https://admin4a.online.lync.com/OcsPowershellOAuth –Verbose

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Moving Users to Teams

To Move users to Office 365, You need to first provide credentials of the User with MFA disabled and then use the command Move-CsUser

An Example:

$Creds = Get-Credential

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Moving User

Move-CsUser –Identity user@domain.com –target “sipfed.online.lync.com” –hostedMigrationOverRideUri https://admin4a.online.lync.com/HostedMigration/hostedmigrationservice.svc –ProxyPool “YourFEPool.Domain.local” –Credential $Creds

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Let’s check the status of the migrated user, The hosting provider attribute is what we care about as it tells us where the user is homed at.

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Checking the user from Teams Portal

Users seems to be licensed, online and can now login using the Microsoft Teams app.

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Bulk Enable Users and assign Tel URI numbers to them

In case you have a big number of users that you want to enable them online

# Please provide your O365 admin credential

$creds = Get-Credential

-PSSession (New-CsOnlineSession $cred) -AllowClobber

$csv = Import-csv “C:\Users\Mohammed\users.csv”

ForEach ($user in $csv) {

Write-host now enabling $user.alias

Move-CsUser –Identity $user.alias –target “sipfed.online.lync.com” –hostedMigrationOverRideUri https://admin4a.online.lync.com/HostedMigration/hostedmigrationservice.svc –ProxyPool “YourFEPool.Domain.local” –Credential $creds

}

The CSV File will look like this

Alias

user@domain.com

user2@domain.com

Errors you might face

Error 1:

When you have your on-premises user enabled for dialin you will probably get the following error if you try to migrate them to Skype for Business online or teams.

Move-Csuser :: HostedMisrat ion fault: Error=(511), Description=(The user could not be moved because he or she is enabled for dial-in conferencing on-premises, but has not been an assigned an Audio Conferencing license in Office 365. Users must be licensed before they can be moved to Teams or Skype for Business Online.)

If you are sure do want to use migrate this user without an Audio Conferencing license, specify the

“BypassAudioConferencingCheck” switch. ) At line: 1 char: 1

clip_image001[4]

The Solution is to either provide an audio conferencing license  or as it is showing in the error itself as it says use the switch -BypassAudioConferencingCheck to ignore that.

Error 2:

When trying to import the session, I got the following error

the runspace state is not valid for this operation for PowerShell Online.

clip_image001[6]

Solution: To overcome this problem you’ll need to use the overridePowershellUri Parameter in the New-CsOnlineSession in order to connect to Skype online powershell.

To get your tenant’s PowerShell URI use the cmdlet Get-CsOnlinePowerShellEndPoint

What you need to use is the AbsoluteUri

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Error 3:

When you try to import the SkypeOnlineConnector module and then run the New-CsOnlineSession cmdlet from Skype for Business Management Shell you’ll get the following error after authenticating.

Sign in

Sorry, but we’re having trouble signing you in.

AADSTS50011: The reply URL specified in the request does not match the reply URLs configured for the application: ‘7716031e-6f8b-45a4-b82b-922b1af0fbb4’. More details: Reply address did not match because of case sensitivity.

Troubleshooting details

If you contact your administrator, send this info to them.
Copy info to clipboard  
  
Request Id:  f0f97265-4669-4e4f-bcf7-609469e92f00
 
Correlation Id:  829c8a2b-f697-416f-bfa6-4a794a229a13

Timestamp:  2021-01-10T23:00:10Z
 
Message:  AADSTS50011: The reply URL specified in the request does not match the reply URLs configured for the application: ‘7716031e-6f8b-45a4-b82b-922b1af0fbb4’. More details: Reply address did not match because of case sensitivity.
     

Advanced diagnostics: Disable
  
If you plan on getting support for an issue, turn this on and try to reproduce the error. This will collect additional information that will help troubleshoot the issue.

image

Solution:

Run the cmdlets from Windows PowerShell as admin not Skype for Business Management shell.

References:

https://docs.microsoft.com/en-us/microsoftteams/upgrade-to-teams-on-prem-overview

https://social.technet.microsoft.com/wiki/contents/articles/34339.skype-for-business-online-enable-your-tenant-for-modern-authentication.aspx

https://docs.microsoft.com/en-us/skypeforbusiness/hybrid/move-users-from-on-premises-to-skype-for-business-online

https://docs.microsoft.com/en-us/microsoftteams/teams-powershell-install

https://docs.microsoft.com/en-us/skypeforbusiness/troubleshoot/hybrid-move-sfb-online/move-csuser-hostedmigration-fault-507

error when Installing Nuget module for Microsoft Teams integration

Story

I got a client requesting to integrate Skype for Business 2015 with Microsoft Teams. Skype for Business 2015 is installed on Windows Server 2012 R2 which has PowerShell 4.0

I already installed PowerShell 5.1 and restarted the server in question.

When I tried to install the Microsoft Teams PowerShell Module to integrate Skype for Business with Teams I got the following error:

image

Error

PS C:\Users\Admin> Install-Module MicrosoftTeams

NuGet provider is required to continue
PowerShellGet requires NuGet provider version ‘2.8.5.201’ or newer to interact with NuGet-based repositories. The NuGet
  provider must be available in ‘C:\Program Files\PackageManagement\ProviderAssemblies’ or
‘C:\Users\Admin\AppData\Local\PackageManagement\ProviderAssemblies’
. You can also install the
NuGet provider by running ‘Install-PackageProvider -Name NuGet -MinimumVersion 2.8.5.201 -Force’. Do you want
PowerShellGet to install and import the NuGet provider now?
[Y] Yes  [N] No  [S] Suspend  [?] Help (default is “Y”): y
WARNING: Unable to download from URI ‘https://go.microsoft.com/fwlink/?LinkID=627338&clcid=0x409′ to ”.
WARNING: Unable to download the list of available providers. Check your internet connection.
PackageManagement\Install-PackageProvider : No match was found for the specified search criteria for the provider
‘NuGet’. The package provider requires ‘PackageManagement’ and ‘Provider’ tags. Please check if the specified package
has the tags.
At C:\Program Files\WindowsPowerShell\Modules\PowerShellGet\1.0.0.1\PSModule.psm1:7405 char:21
+ …     $null = PackageManagement\Install-PackageProvider -Name $script:N …
+   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     + CategoryInfo          : InvalidArgument: (Microsoft.Power…PackageProvider:InstallPackageProvider) [Install-Pac
    kageProvider], Exception
     + FullyQualifiedErrorId : NoMatchFoundForProvider,Microsoft.PowerShell.PackageManagement.Cmdlets.InstallPackagePro
    vider

PackageManagement\Import-PackageProvider : No match was found for the specified search criteria and provider name
‘NuGet’. Try ‘Get-PackageProvider -ListAvailable’ to see if the provider exists on the system.
At C:\Program Files\WindowsPowerShell\Modules\PowerShellGet\1.0.0.1\PSModule.psm1:7411 char:21
+ …     $null = PackageManagement\Import-PackageProvider -Name $script:Nu …
+   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     + CategoryInfo          : InvalidData: (NuGet:String) [Import-PackageProvider], Exception
     + FullyQualifiedErrorId : NoMatchFoundForCriteria,Microsoft.PowerShell.PackageManagement.Cmdlets.ImportPackageProv
    ider

More Details:

Although I have PowerShell 5.1 module installed but still it seems problems wont go away. It’s part of Microsoft’s main requirement to have Windows PowerShell 5.1 and to import the Microsoft Teams Module for an easy installation and integration with Teams as it leverages the Module MicrosoftTeams to make things easy.

When looking at the details of the error, it seems as if PowerShell is trying to connect to a particular link to download and install the NuGet Provider which is part of installing the MicrosoftTeams Module.

The error below can be noticed to be the cause.

image

Resolution:

After doing some digging it turns out that since April 2020 Microsoft has disabled the use of TLS Version 1.0 and 1.1 so people who are working on old Windows Server edition or any application servers that utilize these protocols will now have to force PowerShell or any other app to use the TLS 1.2 Version.

In order to fix this, You will need to run the following Script on your PowerShell as an Admin

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12

See the announcement here:

https://docs.microsoft.com/en-us/powershell/scripting/gallery/installing-psget?view=powershell-7.1

After running this script, I was able to install NuGet and run the installation of MicrosoftTeams PowerShell Module

image

Hope this helps