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Windows Server 2008 R2 Recycle Bin

Posted November 26, 2011    Morgan Holm

Microsoft has included recovery capabilities with every release Active Directory (AD) from Windows Server 2000 on. There is a saying that has been around in IT for a long time, “An administrator is only as good as their last backup”. This is because accidental deletions of a single user object to the removal of hundreds even thousands of objects from deleting an organizational Unit (OU) are still a common occurrence. The increasing use of identity management systems and the use of scripting to automate administration tasks have also increased the risk of populating the directory with bad data. This may lead to applications not function correctly or even have security and regulatory compliance implications.

Windows Server 2008 R2 introduced an optional feature to include a recycle bin for Active Directory to simplify the restoration of accidentally deleted objects compared to prior native capabilities. Before the 2008 R2 recycle bin Administrators had the following options though they have certain limitations.

Pre-Windows Server 2008 R2

Prior to the release of the Windows 2008 R2 Recycle Bin for Active Directory recovering objects was possible using one of two basic methods, authoritative restore from a backup or tombstone reanimation.

Authoritative Restore using the NTDSUTIL command line tools

  • Requires taking a production domain controller offline impacting user and network performance
  • The Administrator performing the restoration needs in-depth knowledge of the recovery process and command line utilities to perform the operation from a system state backup
  • The process consists of many manual steps greatly increasing the time and effort for recovery
  • Parent structures are not automatically recreated nor are group memberships
  • Any modifications made since the last system state backup will be lost
  • See Microsoft KB article 840001 (http://support.microsoft.com/kb/840001) for details on the process

Tombstone Reanimation API

  • When objects are deleted in AD they are moved to the deleted objects container and referred to as tombstoned objects
  • In this process these objects are stripped of the majority of their attributes
  • This keeps the DIT size down because these objects will exist in the deleted items container for the tombstone lifetime which is 180 days by default
  • These deleted objects are also replicated to every domain controller so every DC is updated as to what objects have been deleted
  • Tombstone reanimation is only applicable to objects that have been deleted so modifications to existing objects can not be rolled back
  • The Administrator performing the restoration needs in-depth knowledge of the recovery process and command line utilities to perform the operation
  • The process consists of many manual steps greatly increasing the time and effort for recovery
  • Parent structures are not automatically recreated nor are group memberships
  • The restored objects will be missing the majority of their attributes which will then have to be entered manually

Windows Server 2008 Snapshots using the NTDSUTIL command line tools

  • The Administrator performing the restoration needs in-depth knowledge of the recovery process and command line utilities to perform the operation from a system state backup
  • The process consists of many manual steps greatly increasing the time and effort for recovery
  • Parent structures are not automatically recreated nor are group memberships
  • Any modifications made since the last snapshot will be lost

Windows Server 2008 R2 Active Directory Recycle Bin

Microsoft introduced the Windows Server 2008 R2 recycle bin as an optional feature to improve upon the prior recovery processes. The new recovery option extended upon the tombstone reanimation feature to include all attribute data with restored objects. The 2008 R2 Recycle Bin does not have its own graphical user interface. Administrators can use PowerShell Cmdlets or ldp.exe to perform recovery operations. The feature is not enabled by default and there must be some domain and forest level prerequisites configured prior to enabling the feature. It also changes the way object deletions work.

  • The Active Directory Recycling Bin feature requires a forest functional level of Windows Server 2008 R2 so all domain controllers must also be at Windows Server 2008 R2 level as well
  • This is a forest-wide feature that applies to every domain in the forest
  • Objects that were deleted prior to the Active Directory Recycling Bin feature being enabled cannot be recovered by using the Recycling Bin
  • The Recycle Bin feature cannot be disabled after it has been enabled
  • Once the Recycle Bin feature is enabled, you cannot roll back / lower functional levels
  • If you move to 2008 R2, you will have to upgrade to Exchange Server 2010 as well
  • Deleted objects are no longer stripped of the majority of their attributes so the AD database (DIT) size will increase
  • These larger deleted objects are also replicated to every DC so there will be an increase in replication traffic
  • Existing objects cannot be rolled back to prior values
  • Parent structures are not automatically recreated

BeyondTrust PowerBroker Auditor

The Windows 2008 R2 Recycle Bin offers much better protection than any of the prior native methods for the restoration of objects. To utilize the recycle bin, organizations must upgrade both their AD and Exchange environments to the latest versions and functional levels and must have working knowledge of the AD processes and PowerShell Cmdlets. For organizations looking for a more automated, repeatable and risk adverse method for restoration of both AD and GPO objects, or those companies also requiring advanced “undo” capabilities, a third party solution such as the BeyondTrust PowerBroker Auditor offers unparalleled benefits that include the following.

  • Provides the ability to rollback objects to previous states not just state the object was in as it was deleted
  • Automatically restores parent containers for quicker and easier restorations
  • Does not require Windows 2008 R2 on all domain controllers
  • Does not store all attribute data in AD to reduce space and replication requirements
  • Provides graphical wizard based attribute comparisons and rollbacks
  • Provides wizard based comparison (including merge and side by side) and restore or rollback of GPO objects
  • Provides DC targeting, forced replication and conflict options
  • Provides ability to rollback to previous GPO versions, not just the last deleted state
  • Integrates with auditing to view who made the changes and/or deletions of the objects
  • Auditing module provides real-time alerts to changes and deletions of objects in AD
  • Does not require knowledge of scripting
  • Automated to enforce a repeatable process and reduces the risks of errors
  • Simplifies multi-object operations with graphical interactive targeting, comparison and processing
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