New Microsoft Incident Response guides assist safety groups analyze suspicious exercise

Right this moment Microsoft Incident Response are proud to introduce two one-page guides to assist safety groups examine suspicious exercise in Microsoft 365 and Microsoft Entra. These guides include the artifacts that Microsoft Incident Response hunts for and makes use of each day to supply our clients with proof of Risk Actor exercise of their tenant.

With greater than 3,000 totally different actions (also called operations) logged into the Microsoft 365 suite, understanding that are helpful to your investigation might be daunting. With these guides, our objective is to make triaging and analyzing information in Microsoft 365 easier. Many of those operations are data-based storytelling automobiles, serving to Microsoft Incident Response to piece collectively an assault chain from starting to finish. Now we have labored on lots of of cloud-centric circumstances with our clients, and whereas techniques, strategies, and procedures (TTPs) change with the occasions, evaluation methodology and information triage strategies stay persistently profitable. To allow Microsoft Incident Response to search out floor reality rapidly and successfully in an investigation, information mining primarily based on recognized components is important. The recognized components might be investigation particular, reminiscent of an IP handle, recognized compromised username, or suspicious consumer agent string. It is usually simply as vital to filter primarily based on how actors transfer via a cloud surroundings and collect information. That is the place these guides come into their very own, and our hope is that sharing these guides may help you in the identical means they assist us day-after-day.

Analyze the Unified Audit Log in Microsoft 365

First up is our normal Microsoft 365 information, centered round key actions in Change On-line and SharePoint—Microsoft 365 merchandise generally focused in cybersecurity assaults. Take into account that the motives of a Risk Actor, the instruments obtainable to them, and the extent of entry they’ve achieved will decide the actions they take. No two incidents are ever the identical.

Actions carried out in a tenant are recorded within the Unified Audit Log, which might be accessed from the Safety Portal or via PowerShell. You’ll be able to filter the audit log by date, consumer, exercise, IP handle, or file title. You may also export the audit log to a CSV file for additional evaluation.

A lot of the operations in these sheets are self-explanatory in nature, however just a few deserve additional context:

SearchQueryPerformed—A consumer or an administrator has carried out a search question in SharePoint On-line or OneDrive for Enterprise. This operation returns details about the search question, such because the IP handle, however doesn’t return the question textual content.

SearchQueryInitiatedSharePoint and SearchQueryInitiatedExchange—These operations are solely logged you probably have enabled them utilizing the Set-Mailbox PowerShell cmdlet. This operation is very like SearchQueryPerformed, besides it incorporates the search question that was used.

SearchExportDownloaded—A report was downloaded of the outcomes from a content material search in Microsoft 365. This operation returns details about the content material search, such because the title, standing, begin time, and finish time.

Replace—A message merchandise was up to date, together with metadata. One instance of that is when an e-mail attachment is opened, which updates the metadata of the message merchandise and generates this occasion. An replace operation just isn’t at all times indicative of an e-mail message being purposefully modified by a Risk Actor.

FileSyncDownloadedFull—Person establishes a sync relationship and efficiently downloads recordsdata for the primary time to their laptop from a SharePoint or OneDrive for Enterprise doc library.

Detailed id and entry information with Microsoft Entra

Our Microsoft Entra information covers actions which permit organizations to handle and defend their identities, information, and units within the cloud. As an industry-leading id platform, Microsoft Entra ID provides superior safety features, reminiscent of multifactor authentication, Conditional Entry insurance policies, id safety, privileged entry administration, and id governance.

To view the actions carried out by customers and directors in Microsoft Entra ID, you should utilize the Microsoft Entra ID audit log, which shops occasions associated to position administration, system registration, and listing synchronization to call just a few. To view detailed sign-in info, you should utilize the Signal-In Logs. The occasions situated in these two information sources may help you detect and examine safety incidents, reminiscent of unauthorized entry or configuration adjustments to the id aircraft.

You should utilize the next strategies to entry Microsoft Entra ID audit log information:

Microsoft Entra Admin Portal—Go to the portal and sign up as an administrator. Navigate to Audit and/or Signal-ins below Monitoring. Filter, kind, and export the info as wanted.

Azure AD PowerShell—Set up the Azure AD PowerShell module and connect with Microsoft Entra ID. Use Get-AzureADAuditDirectoryLogs and/or Get-AzureADSignInLogs to get the info you want. Pipe the outcomes to Export-CSV to output the data for evaluation.

Microsoft Graph API—Register an utility in Microsoft Entra ID and provides it the permissions to learn audit log information (AuditLog.Learn.All and Listing.Learn.All). Use /auditLogs/directoryAudits and /auditLogs/signIns API endpoints to question the info, together with question parameters reminiscent of $filter to refine the outcomes.

A lot of the operations in these sheets are self-explanatory in nature, however as with our Microsoft 365 operations, just a few deserve additional context:

Suspicious exercise reported—This log occasion signifies {that a} consumer or an administrator has reported a sign-in try as suspicious. The log occasion incorporates details about the reported sign-in—such because the consumer, the IP handle, the system, the browser, the situation, and the chance stage. It additionally exhibits the standing of the report—whether or not it was confirmed, dismissed, or ignored by the consumer or the administrator. This log occasion may help determine potential safety incidents, together with phishing, credential compromise, or malicious insiders.

Replace utility: Certificates and secrets and techniques administration—This log occasion signifies that an administrator has up to date the certificates or secrets and techniques related to an utility registered in Microsoft Entra ID—reminiscent of creation, deletion, expiration, or renewal. Purposes are regularly misused by Risk Actors to realize entry to information, making this a essential administrative occasion if discovered throughout an investigation.

Any operation ending in ‘(bulk)’—These are attention-grabbing as they exhibit a bulk exercise being carried out—reminiscent of ‘Obtain customers’ or ‘Delete customers.’ Take into account, nonetheless, that these are solely logged if the majority exercise is carried out utilizing the graphical consumer interface. If PowerShell is used, you’ll not see these entries in your log.

Elevate Entry—Assigns the at present logged-in id the Person Entry Administrator position in Azure Position-Based mostly Entry Management at root scope (/). This grants permissions to assign roles in all Azure subscriptions and administration teams related to the Microsoft Entra listing. This toggle is simply obtainable to customers who’re assigned the International Administrator position in Microsoft Entra ID. It may be utilized by Risk Actors to realize full management of Azure sources, typically for the needs of crypto mining or lateral motion from cloud to on-premises.

Enhance safety evaluation with the Microsoft Incident Response guides

We hope that these one-page guides shall be a helpful useful resource for you when you should rapidly determine and analyze suspicious or malicious exercise in Microsoft 365 and Microsoft Entra ID. Print them out, save them as your desktop background, or put them on a mouse pad. No matter you do, tell us what you discover helpful and do not forget that the audit logs in Microsoft 365 and Microsoft Entra ID usually are not the one supply of proof in a cloud-based case, and it’s best to at all times correlate and validate your findings with different information sources the place doable.

To entry additional info on what information lies in these logs and how one can entry them, reference the next weblog posts from the Microsoft Incident Response crew:

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