Posted by Ahmed Nabil In , | 0 comments»
Several users started receiving certificate expiration warning messages on their computers regarding specific user certificates. Upon checking this certificate it turned out to be Lync Communication certificate as per the below screen shot.




This message is a normal Windows Warning Notification regarding a user certificate stored in the personal certificate store of the user account logged on this machine. In this specific case it was Microsoft Lync Communication certificate. When the Lync communication certificate expires, the client will just receive new certificate for the user SIP URI and everything should work normal.

However to manually stop receiving the warning shown above the user can check the box near the certificate and click done.

The question is why all users in the domain started getting these warning messages. To identify the root cause, i ran a GPRESULT from one of the client computers and i noticed a group policy configured across the domain with these warning settings. These specific settings are located under

User Configuration/Windows Settings/Security Settings/Public Key Policies/Certificate Services Client – Auto-Enrollment Settings”


There is a checkbox as shown below for the Expiration Notification when the the given percentage of certificate lifetime is reached. To avoid getting these warning you can remove/uncheck this option and users won't receive this notification.



It should be noted that if there is no group policy set, the users won't get any notification and won't even notice that the certificate expired and they got a new one.




مايكروسوفت EMET 4.1 - الجزء 1

Posted by Ahmed Nabil | 0 comments»




Microsoft EMET 4.1 tool Part 1 for Basic Installation and configuration in Arabic



Force Log off of idle Remote sessions on Server 2008 R2

Posted by Ahmed Nabil | 0 comments»
Normally IT users will connect to the servers using RDP/MSTSC to administer and configure their servers, However they will mostly leave their sessions and forget to log off after doing their work especially if its long task or they are used to connect to these servers on regular basis. This can cause several security issues as well as account problems especially if the user changed his password while there is a session logged on another sever.

You can easily Force log off of idle sessions on remote servers by creating a scheduled task on these servers. In the below example i would assume forcing idle sessions to log off after one hour.

To create the needed task you need to do the following:

  1. Open the Task Scheduler, Click Task Schedule library
  2. Create New Task
  3. Type the name of the task and select "Run with Highest Privilege" check box                                                                                                                                                                                          
  4. On the triggers click New and check "On Idle"                                                                                                                      
                                                   
  5. From the Actions, Click New and choose the logoff.exe (The default path of the logoff.exe is C:\Windows\System32)                                                                                                                                           
                                                         
  6. In the Conditions Tab, Set the idle time. In this example, the idle time is 1 Hour.                                                                               
                                                   
Its a simple solution but would fix the problem of several idle connections on the server blocking other users to connect (I am mainly talking about normal servers with no Terminal server role installed where you have only two sessions available for remote users).






SCOM Event 26004, Health Services Module. Hyper-V Image Management Service admin Event Log

Posted by Ahmed Nabil In , | 0 comments»
I was working lately on Migrating and moving all our Virtual Machines from Hyper-V 2008 R2 Hosts to the latest 2012 R2 Hyper-V Hosts. We installed the Hyper-V 2012 and 2012 R2 SCOM Management Packs to monitor our new servers while keeping the old 2008 Hyper-V Management Pack since there are still VMs hosted on 2008R2 (Transition Phase).

It was noticed that Event ID 26004 is repeated on daily basis on my Hyper-V 2012 R2 Host servers under the Operations Manager logs from Server Event Viewer.



The Image Management Service Admin Event log was only available back in Hyper-V 2008 R2 Hosts and it doesn't exist in Hyper-V 2012 or 2012 R2



Problem

On my SCOM server i have three Hyper-V Management Packs for 2008R2, 2012 and 2012R2 Hyper-V hosts. Logically each Management Pack should identify and point all its monitors to its relevant servers. However it looks like the 2008R2 Management Pack which includes the Image Management Service admin Event log is pointing and trying to get this data from the 2012 and 2012 R2 servers

Upon checking this issue with several Microsoft Support engineers, they confirmed that when the 2008 R2 Management Pack was created the work flow was targeted very broadly and affected all Hyper-V hosts, Even if you have the correct Management pack as 2012 or 2012 R2, this won't stop the 2008 MP to monitor and target the newer Hyper-V servers.

Solution

The Solution is to disable targeting this monitor from the 2008 MP to 2012 and 2012 R2 servers

In order to do this you need to do the following:

1. Go to the SCOM Console, Authoring - Management Pack Objects - Monitors - find - mounted drive



2. To confirm that this Monitor although is 2008 its targeting also 2012 and 2012 R2 you need to check from the SCOM Console the Monitoring - Discovered Inventory and change Target type to Hyper-V Virtual Hard Disk, you will find all Hyper-V servers are listed and not only 2008 R2 Hosts.

3. From the Authoring - Groups -create new group, select a name and place it in new customized Management Pack.

4. In the Explicit Members - Click add/remove object. Add all 2012 R2 and 2012 Servers and disks (Search for Hyper-V Virtual Hard Disk and Widows server 2012/2012 R2 Full computer)



5. Right Click the SCOM Monitor (Hyper-V Virtual Hard Disk - Mounted drive Read-Only ), disable the monitor - For a group and pick the group created in Step 3. Enable & Enforce the Override as per attached.







This should fix the problem. Also if all VMs are migrated lately to 2012 R2 or 2012 Hosts and there is no more 2008R2 Hyper-V hosts in the environment, you can delete the 2008 Hyper-V Management Pack from SCOM to avoid this issue or similar ones.




Microsoft Enhanced Mitigation Experience Toolkit (EMET) 4.1 Technical Review - Part 1

Posted by Ahmed Nabil | 1 comments»
Microsoft Enhanced Mitigation Experience Toolkit (EMET) is a must tool from my point of view for any security professional as well as normal users to help protect them from unknown vulnerabilities or what so called Zero-Day attacks. EMET will try to stop and prevent the malicious code from running however this doesn't mean the vulnerability is fixed. Still you need to check with the software or OS vendor for the latest updates and patches. In these series of blog posts, i will try to cover EMET, installation, configuration for home users or Enterprise customers using Group policies and some tips and tricks especially with 3rd party applications.

EMET provides multiple mitigation as the Data Execution Prevention (DEP), Structured Exception Handler Overwrite Protection (SEHOP), Null Page Allocation, ASLR........etc. and other well known mitigation techniques.

One of my favorite is the Certificate Chain Trust where EMET will run while connecting to an HTTPS site and validate the other end SSL certificate and the Root Certification Authority (CA) that issued this certificate versus the corresponding pinning rule configured by the user, this is very beneficial to detect the man-in-the-middle-attacks.

The latest current public version is EMET 4.1 released on December 2013 and it can be downloaded from http://www.microsoft.com/en-eg/download/details.aspx?id=41138

EMET 5.0 was released for preview couple of days ago and its available for testing and customers feedback, the final release should be released sometime this year. For more info you can check this link https://blogs.technet.com/b/srd/archive/2014/02/25/announcing-emet-5-0-technical-preview.aspx


What are EMET 4.1 Requirements:


  1. Dot Net Framework 4
  2. For Windows 8 and IE 10 Protection you need to have KB2790907

Installation Steps for Standalone users:

  1. EMET installation is straight forward, just few Next clicks and you are done.
  2. The final screen in EMET installation is where you will choose between the Recommended settings or manual settings. For now we will choose Recommended settings.
  3. After installing EMET and if you wanna get back to this configuration wizard then you need to click on the Wizard button on EMET Home as shown below.


 

The bottom of EMET main page shows the Running Process, since EMET default configuration enables protection for Microsoft Internet Explorer so when i opened Internet Explorer to browse the Internet it get listed in the running process with green check to confirm that EMET is enabled on it.


In the next blog post i will explain deployment and configuration using Group Policies for Enterprise Customers and Organizations. See you all then and for the meantime try to install EMET with default configuration and play around with it.







Lync Mobile phone lose Server Connection "Cannot Connect to Server, Retrying........"

Posted by Ahmed Nabil In | 1 comments»
Mobile or Tablet users using the Latest Microsoft Lync 2013 Client on their phone OS (IOS, Android or Windows 8 Phone) may lose server connection during the Lync call and get this message displayed in the Lync program.

"Cannot connect to server, Retrying............."

I encountered this message myself on several occasions during a Lync call using my mobile device. The Lync 2013 mobile version will establish connection to the Lync Reverse Proxy (It can be Microsoft TMG 2010 or IIS ARR). In my case I am using the IIS ARR which is highly recommended now by Microsoft (Actually Microsoft is pushing for this method) since Microsoft discontinued any future release for TMG 2010.

To solve this issue, i increased the Time-out setting in the IIS Server Farm Proxy as follows:


  • Open IIS on the Reverse Proxy server and Navigate to the Server Farm.


  • Open the Proxy and increase the time-out settings (Default is 200)



This should be done to both the Lync Discover and External Web Services URL/Farm.


For more information about the recommended/Qualified Infrastructure for Lync 2013, check the following URL  http://technet.microsoft.com/en-us/lync/gg131938


Microsoft Extends Antimalware/Antivirus Support for Windows XP to July 2015

Posted by Ahmed Nabil In , | 1 comments»
Microsoft Announced couple of days ago that it will extend its support for Antimalware and Antivirus products running on Windows XP till July 2015. This is really good news for Enterprises moving and migrating from XP to newer versions as well as personal users and individuals with Windows XP.

Microsoft earlier announced that Windows XP end of support is April 8, 2014 which includes any support for bugs, security issues or any Operating system support. On top of that was the Antimalware and Antivirus signatures.  Windows XP operating system launched more than 10 years ago was a very successful OS for Microsoft and was highly adopted by Organizations and personal computers. According to recent statistics Windows XP is being used on almost 30% of Desktops as per below Market share Statistics Link.

http://marketshare.hitslink.com/report.aspx?qprid=11&qpaf=&qpcustom=Windows+XP&qpcustomb=0

This was probably the main reason for Microsoft to Extend the Anti Malware/Virus Support for another year after the XP end of support. This extension applies to enterprise users running System Center End Point Protection, Forefront Client Security and Forefront Endpoint Protection. Also Personal users running Security Essentials will be covered as well.

For more details please check the below link.


http://blogs.technet.com/b/mmpc/archive/2014/01/15/microsoft-antimalware-support-for-windows-xp.aspx


This extension will not stop the XP end of support scheduled April, 2014. There will be no Security or Critical updates for Windows XP after April, 2014. Its still highly recommended to move ASAP to newer version of Windows for full support.

Surface 2 RT Bitlocker Recovery Key problem is fixed

Posted by Ahmed Nabil In | 3 comments»
Windows Surface 2 RT comes already pre-setup with Bitlocker encryption, the user don't need to do anything to enable it or set/type a password to access the drive or wait for encryption time. This is very cool feature to protect and encrypt your data and files on the Surface. Its automatically enabled and turned on when users open the Surface for the first time, set it up and login with their Windows account (Outlook, Hotmail.....etc.)


The Key thing to note is that the Recovery key is stored on your Skydrive as soon as you login on the surface with your Microsoft account. If you need to recover your key you will need to login to Skydrive (http://www.skydrive.com/recoverykey) from another computer, phone or tablet and get the key and enter it to the Surface Recovery prompt on your surface.


This sounds normal if you are aware of this procedure and doing some action that requires you to get the Bitlocker Recovery key. However several users including my self encountered this problem on Surface 2 (Not Surface Pro). After rebooting your surface device or turning it on from a shutdown you may get a Prompt to Enter Bitlocker Recovery Key. After entering the recovery key the Surface will hang on 0% with the new nice blue screen of death and an error displayed at the bottom PAGE_FAULT_IN_NONPAGED_AREA.


The Problem is that this issue occurred randomly (Some users related it to new firmware update but it was never confirmed as other users installed the same firmware without any problem) and users are not aware of this Skydrive Recovery procedure and the main thing is that sometimes they may get this error/problem without having another device to access the Internet and get their recovery key.

Microsoft confirmed the problem and a fix was finally released to close this issue yesterday. For More information and to download this fix, please check the below site.

http://support.microsoft.com/kb/2921482

I installed the fix using Windows update and it went fine and I am monitoring my device for any side issue.

Bye Bye Microsoft UAG !

Posted by Ahmed Nabil In | 0 comments»
Yesterday Microsoft Announced officially that there will be no new future full version of Microsoft UAG. Server 2012 and 2012R2 will cover some of the UAG features as Direct Access and basic secure application publishing. This was quite expected especially after the TMG retirement and the new web application proxy that was introduced in Server 2012 R2.


For more details on the latest changes to the Forefront family, please check the below article

http://blogs.technet.com/b/server-cloud/archive/2013/12/17/important-changes-to-the-forefront-product-line.aspx