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Office 365

Office 365 is a package of software provided as service on cloud platform. The cloud based service offers productivity through subscription packages that enable on-premise services to be available on cloud for different levels of organizational usage. The platform altogether promotes a new method of purchasing the applications of Office suite. The extensive usage of this software-service provider in businesses and enterprises makes it a platform known best for the rich exchange & storage of confidential information using Exchange online service. The Exchange mailbox repository holds sensitive corporate storage in Office 365, which turns out to be a critical element during investigative procedures carried out on cloud for the discovery of artifacts.

Administrators and Exchange Online

The administration of Exchange online is executable via:

  1. A Web Console
  2. Remote Session for PowerShell

Web Console represents a collection of consoles where the top-level console is of Office 365 featuring the basic settings for the offered services. In addition, there is a respective product based consoles each for; Exchange, Lync, and SharePoint.

Investigative Standpoint

Before the 2013 release, Web Console acted as a second-class interface whereas, PowerShell did most of the tasks. Soon, the platform underwent evolution and resulted in became the primary interface for Administrators of Office 365.

In-Place eDiscovery & Hold - Office 365

In-Place eDiscovery is a powerful integrated facility with which, a user having required permissions, can gain access of the entire messaging records of an Exchange organization. The Discovery Management role group is a crucial element. Therefore, it is important to ensure proper control & monitoring on the discovery related activities.

Measures to be taken to ensure a controlled Discovery Management Group:

  1. Limited & careful addition of members to the role group
  2. A check on the discovery activities performed on the role group
  3. The allotment of roles like the Mailbox Search management
  4. Access permission for discovery mailbox usage allotment

Advantage: The feature is offered in a user-friendly manner with self-descriptive options that can easily be adopted by record managers, legal & compliance officer, along with professionals from the human resource department for eDiscovery purposes. Search feature comes with a variety of criteria to be implemented for detailing the search for particular messages from selected mailboxes.

Limitation: A maximum of only 2 In-Place eDiscovery searches can be conducted at a time within an organization. Moreover, there also exists a limit on the number of source mailboxes to be searched (applicable mostly on large-scale enterprises).

Office 365 Forensics - In-Place eDiscovery

The Exchange Admin Center provided on the web console for Exchange features a user-friendly search option that can be implemented for eDiscovery purposes.

Stages of eDiscovery

For users with authorized permission, it is feasible to execute an In-Place eDiscovery lookup in the following stages:

  • Selection of the preferred mailbox
  • Specification of search criteria in the form of:
  • Keywords
  • Dates from start to end
  • Addresses of the recipient and sender
  • Message type, etc.
  • Post search completion, users can choose one from the given actions to be performed on the search result:
  • Estimate: An estimate value of the total size along with number of items is returned for the performed search (based on the specified criteria).
  • Preview: Preview of the search results is provided, i.e. messages targeted from the selected mailbox(s) are offered for preview.
  • Copy: Enables the copying of messages to a discover mailbox
  • Export: Post copying of messages to discover mailbox, export to a PST file can be performed for their local storage.

Audit Trails in Office 365

Audit trails are a facility using which, the track of target mailbox(s) can be maintained. Performing a mailbox audit logging can help track the actions executed by mailbox owners, delegates, and administrators on the target mailbox. The three ways in which auditing can be carried out are:

  • Mailbox access auditing
  • Admin auditing
  • Canned reports

Advantage: Audit Trails offers great benefit for tracking certain number of mailboxes and keeping a check on the activities performed on them whether by delegates, administrators or users.

Limitation: Auditing is not enabled by default and has to be activated for use. The default settings in auditing are awful and therefore, the criteria must be specified before starting up with the investigation.

Auditing Office 365 Mailboxes

Before performing the auditing of mailboxes, residing on Office 365 it is important to know that:

  1. Audit log entries are only sustained for duration of 90 days within the mailbox by default. Change it.
  2. Administrator with Full Access permission to a mailbox is officially a delegate user.
  3. Exchange Admin Center cannot be used for audit logging instead remote PowerShell in connection with Exchange online is required.
  4. On enabling the option for audit logging of mailbox(s), a certain number of actions carried out by admin or mailbox delegates are automatically logged. Change it.

Stages of Auditing

  • Establish connection with Exchange Online remotely accessing PowerShell

\$UserCredential = Get-Credential \$Session = New-PSSession –ConfigurtionName Microsoft.Exchange –ConnectionUri -Credential \$UserCredential –Authentication Basic –AllowRedirection Import-PSSession \$Session Get-Mailbox

  • Enable the audit logging of mailbox

Set-Mailbox –Identity “PiPi” –AuditEnabled \$true

Get-Mailbox –ResultSize Unlimited –Filter {RecipientTypeDetails -eq “UserMailbox”} | Set-Mailbox -AuditEnabled \$true

  • Mention the owner actions for auditing (Optional)

Set-Mailbox “PiPi” –AuditOwner MailboxLogin,HardDelete

Set-Mailbox “Doll” –AuditEnabled \$true –AuditOwner HardDelete

  • Change retention duration for the entries in mailbox audit log (Optional)

Set-Mailbox –Identity “PiPi” –AuditLogAgeLimit 180

Get-Mailbox –ResultSize Unlimited –Filter {RecipientTypeDetails –eq “UserMailbox”} | Set-Mailbox –AuditLogAgeLimit 60