Tag: Windows 10

WIndows 10 Annual update error 0xc1900200

Published on in Windows by Elvis

I recently bought Minix Z83 mini PC and the first think I did was to upgrade it to the latest version of OS. Unfortunately, I received immediately an upgrade error with a code 0xc1900200. This means that UEFI partition on the disk is too small. It should be at least 350MB, but deployed size is 64MB.
Well, no problem, you have just to resize the partition and this is very simple. I use a tool named EaseUS Partition Master, which gave me very good results everywhere. But there was a second disappointment: I was not able to move or resize the partition “Other” with size 16MB and in Minix forums there is no explanation what this partition is used for or if I can delete it.
I did some research what to do with current file system, why we have an additional partition and finding some answers I decided to delete this 16MB partition.
So, my steps to solve the problem were:

  • Install and start EaseUS Partition Master
  • Resize the system partition (C:) in a way to reduce size for 270MB and apply free space in a front of partition
  • Restart the computer (EaseUS needs to restart a computer to apply changes on system partition)
  • Start EaesUS Partition Master again
  • Delete the partition with the size 16MB
  • Resize UEFI partition to 350MB
  • Apply all changes (You can see the final situation on the image)
  • Close EaseUS Partition Master and restart the computer
  • Update Windows with Windows 10 Upgrade Assistant.


This step will guarantee you to upgrade your OS to the latest version and avoid problems in the future. The steps are valid also for other systems and other configurations, but be careful when you have more than only needed partitions. Any additional partition is there for some reason and is better to find why before you remove or resize it.

WannaCrypt Malware

Published on in Essentials Server, Management, Windows, Windows SBS Server, Windows Server by Elvis

Of course you have heard about the new malware, which yesterday created a lot of problems in industry. Unfortunately it is not an unknown problem.
Microsoft released a patch for this type of vulnerability already in March, but it seems once again that administrators are not patching their systems.
So, if you haven’t patched your systems at least every month, if you haven’t patched your system from March, is time to do it. And don’t forget to have a good defense system (antivirus and other prevention mechanisms). Update them to!
You can find additional information in this link.

Here is a link to post how was neutralized and who did this.
Anyway, we have already a version 2.0; you can read about this version here.
Again, please patch your systems! This update will solve a vulnerability. And don’t forget: this is not the first malware who was written on known vulnerability – patch your systems constantly!
Additionally, please disable SMB1 protocol – it is not new that it is not secure. Here and here are some guidelines how to do it via GPO.

Have your forgotten your Local Administrator password?

Published on in Uncategorized, Windows, Windows Server by Elvis

Well, if the computer is yours and you have physical access to it, than you can solve it.
This procedure will work with Windows 8.x and newer and Windows server 2012 and newer. It is not a real hacking technology, but we will use a hole of the operating system.
All we need in this case is to open a shell with enough high privileges before we are asked for the password. Impossible? Not really.
We will do it in a simple way:

  • Insert installation media to your computer and start it from installation media
  • In installation process select Repair your computer

  • In Choose your option select Troubleshoot and then Command prompt

  • Find the partition where Windows are installed (default is C:) and change directory to Windows\System32 (cd \\Windows\\System32)
  • For server systems you have to rename file “UserInit.exe” to something else, using command Ren UserInit.exe Userinit.Old and replace the missing file with cmd by copying a file with command copy cmd.exe userinit.exe
  • For windows systems you have to rename the file “Utilman.exe” to something else, using the command Ren Utilman.exe Utilman.Old and replace the missing file with cmd by copying a file with command copy cmd.exe Utilman.exe

  • Restart the computer to boot into normal operating system (where you forgot the password)
  • Click on Easy of Access icon and a Command prompt window will open. To clarify, this Command shell is opened as system, so you can do a lot of things here.

  • If Administrator account is disabled (Windows 8.x or 10), first you need to enable it with command Net user Administrator /enable:yes
  • Reset password of Administrator account with command Net user Administrator MyPassword, where MyPassword is your new password

  • Close command prompt and login to your System.

Do not use this procedure for hacking. This article is meant for recovering your passwords and passwords for your clients and will not recover domain passwords.

Kaspersky cause Hyper-V error 0x80070005 when creating switch

Published on in Management, Virtualization, Windows, Windows Server by Elvis

Kaspersky Hyper-V ErrorAs I trust and use Kaspersky Antivirus, I had some problems in last month or two. It seems that Kaspersky is not really well integrated with Windows 10 and you have to expect some problems.
In my case, I use Kaspersky Small Office Security and this software prevents me to do a lot of actions. I found the issue when I tried to create External Network Switch in Hyper-V console – the problem is when you create a new network adapter. In this case I received an Error Access Denied – 0x80070005.
I received the same Error also when I tried to install Shrew Soft VPN Client. I was always unable to install network component due to Access Deny.  Analyzing the problem, I found that there is a problem accessing to folder INF (Change) and some other system folders, but all permissions were as they should be and there was no way to establish the right permissions to get installers work.
Well, removing Kaspersky I was able to solve the problem. But be careful, just disabling the antivirus will not be enough; you have to completely uninstall the entire antivirus and reboot the computer to correct the issue.
Hope that Kaspersky will correct the issue soon. It is my preferred antivirus program and I like it, but unfortunately it is not well integrated with Windows 10.

Cryptolocker…

Published on in Essentials Server, Management, Uncategorized, Windows, Windows Server by Elvis

Everyone of us want to stop Cryptolocker and similar programs. It seems that it is really a nightmare for all admins. Anyway, to stop Cryptolocker and any unwanted program, you have to be aware, that this will bring limitations to your system, which are not always welcome.

How does Cryptolocker work?
We have 5 phases of Cryptolocker infections:

  1. Installation: The software is delivered to your computer via download or E-Mail attachment and the user click on it. The executable is now installed, the registry keys are set and we are ready to go to the next phase.
  2. Contacting headquarters: the computer is contacting criminal headquarters for registration, so it will prepare all environment for phase 3.
  3. Creating keys: headquarter and client are now identifying each other and are ready to “handshake” and create two keys for encryption.
  4. Encryption: Cryptographic keys are now established and the encryption can begin. It depends on version, but almost all files on all local and shared drives where you have permissions will be encrypted.
  5. Extortion: The screen with a guide how much and where to pay is displayed. There is displayed also how much time you have for payment. If you will not pay in time, the headquarter key will be deleted and you will not be able to decrypt files. The payment is every day higher – so if you want to pay, do it immediately.

To prevent a large number of unwanted software, the first step to do is always remove LocalAdmin permissions and turn on UAC. This two actions will put you in situation where user will not be able to install any application and write to system crucial folders. Also have your system always up to date. And I don’t mean only OS, but include all applications installed (we know attacks to Java, Adobe FlashPlayer, Microsoft Office…).
Of course this is not enough as a lot of bed guys know how to elevate permissions or are using different folders (for example AppData is used for Cryptolocker), but been a LocalAdmin is a great way to become a victim. I suggest to all home users and system administrators to use two different accounts – one for daily use and the second for administrator tasks.
Well, the real way to prevent Cryptolocker is blocking the execution of exe files in AppData folder. You can do this with group policy in AppLocker or in software restriction policy. This are steps for basic protection with AppLocker:

  1. Create new GPO for Cryptolocker prevention
  2. Edit new created GPO
  3. Expand Computer configuration > Policies > Windows Settings > Security settings > System Services
  4. Enable “Application Identity” service and set it to automatic startup modeCrypto1
  5. Go down to Application Control Policies and expand to AppLocker
  6. In “Configure role enforcement enable Executable rules and make them in Enforce mode (I suggest you, to run them in Audit mode for week or two and analyze logs before enforcing them – just to find legal applications which can be blocked)Crypto2
  7. Expand AppLocker and click to Executable rules
  8. Right click in action pane and create Default Rules
  9. Right click in action pane and create New RuleCrypto3
  10. In Permissions on Action set Allow for EveryoneCrypto4
  11. In Conditions select that is Publisher ruleCrypto5
  12. In Publisher, just browse one file (in my case was Internet Explorer) and go with slider up to Any publisherCrypto6
  13. Give the name to the ruleCrypto7

So, this is about AppLocker, but we have still a lot of work to do. There is a big surface for attack if users are local admin. To prevent this, configure Restricted groups in GPO by using Computer Configuration > Policies > Windows Settings > Security settings > Restricted Groups.
Apply this GPO to all computers and the first step is done.
GPO is a good way to prevent Crypto, but be aware that Crypto is evolving and you have to evolve with him. And preventing Crypto with GPO means that executable is already in your system – maybe you have to prevent it before is downloaded or received with mail. For this step you will need the application firewall, good antivirus in file system and in mailing system.
But still you can do something with chip devices with closing outgoing ports 83, 846, 777, 997, 1604, 9001, 9003, 444, 9052, 8443, 7777, 9003 and 25254. This ports are used to communicate with headquarter servers to obtain a certificate for encryption (maybe exist also other ports or will be added / changed during the time). If you will close this ports, the system will not be able to retrieve a certificate for encryption and the encryption will not be able to begin. Be careful on notebooks because the users will bring their notebooks at home and the encryption will be successful.
As you can see, there are a lot of ways to prevent Cryptolocker, but you have to prevent it. When you have it, it is too late – think about it now!

And for home users? Well we cannot forget them. They have a lot of pictures and documents on their computers – practically a whole life and is a really big impact to lose all this material.
I suggest you a software from FoolishIT. It is free and it is working good (but if you want to keep it up to date, give those few Euros to the author – he is doing his job well!).

 

Additional reading:
https://blogs.technet.microsoft.com/mmpc/2015/01/13/crowti-update-cryptowall-3-0/
http://www.crowdstrike.com/blog/4-0-another-brick-in-the-cryptowall/
http://researchcenter.paloaltonetworks.com/2015/02/analysis-cryptowall-3-0-dyre-i2p/
https://tools.cisco.com/security/center/viewAlert.x?alertId=36338