Adversaries may leverage information repositories to mine valuable information. Information repositories are tools that allow for storage of information, typically to facilitate collaboration or information sharing between users, and can store a wide variety of data that may aid adversaries in further objectives, or direct access to the target information. Adversaries may also abuse external sharing features to share sensitive documents with recipients outside of the organization.
The following is a brief list of example information that may hold potential value to an adversary and may also be found on an information repository:
Information stored in a repository may vary based on the specific instance or environment. Specific common information repositories include web-based platforms such as Sharepoint and Confluence, specific services such as Code Repositories, IaaS databases, enterprise databases, and other storage infrastructure such as SQL Server.
Consider periodic review of accounts and privileges for critical and sensitive repositories.
|M1018||User Account Management||
Enforce the principle of least-privilege. Consider implementing access control mechanisms that include both authentication and authorization.
Develop and publish policies that define acceptable information to be stored in repositories.
|ID||Data Source||Data Component|
|DS0015||Application Log||Application Log Content|
|DS0028||Logon Session||Logon Session Creation|
As information repositories generally have a considerably large user base, detection of malicious use can be non-trivial. At minimum, access to information repositories performed by privileged users (for example, Active Directory Domain, Enterprise, or Schema Administrators) should be closely monitored and alerted upon, as these types of accounts should generally not be used to access information repositories. If the capability exists, it may be of value to monitor and alert on users that are retrieving and viewing a large number of documents and pages; this behavior may be indicative of programmatic means being used to retrieve all data within the repository. In environments with high-maturity, it may be possible to leverage User-Behavioral Analytics (UBA) platforms to detect and alert on user based anomalies.
The user access logging within Microsoft's SharePoint can be configured to report access to certain pages and documents.  Sharepoint audit logging can also be configured to report when a user shares a resource.  The user access logging within Atlassian's Confluence can also be configured to report access to certain pages and documents through AccessLogFilter.  Additional log storage and analysis infrastructure will likely be required for more robust detection capabilities.