At this time 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 comprise 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 (often known as operations) logged into the Microsoft 365 suite, realizing that are helpful in your investigation could be daunting. With these guides, our objective is to make triaging and analyzing knowledge in Microsoft 365 easier. Many of those operations are data-based storytelling autos, serving to Microsoft Incident Response to piece collectively an assault chain from starting to finish. We’ve got labored on lots of of cloud-centric circumstances with our clients, and whereas techniques, methods, and procedures (TTPs) change with the instances, evaluation methodology and knowledge triage methods stay constantly profitable. To allow Microsoft Incident Response to seek out floor reality shortly and successfully in an investigation, knowledge mining based mostly on identified elements is important. The identified elements might be investigation particular, corresponding to an IP handle, identified compromised username, or suspicious consumer agent string. Additionally it is simply as essential to filter based mostly on how actors transfer by a cloud atmosphere and collect knowledge. That is the place these guides come into their very own, and our hope is that sharing these guides might help you in the identical manner they assist us day by day.
Microsoft Incident Response guides
These new one-page guides from Microsoft Incident Response helps safety groups analyze cyberthreat knowledge in Microsoft 365 and Microsoft Entra.
Analyze the Unified Audit Log in Microsoft 365
First up is our normal Microsoft 365 information, centered round key actions in Alternate On-line and SharePoint—Microsoft 365 merchandise generally focused in cybersecurity assaults. Understand that the motives of a Risk Actor, the instruments out there 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 could be accessed from the Safety Portal or by PowerShell. You may filter the audit log by date, consumer, exercise, IP handle, or file identify. It’s also possible to export the audit log to a CSV file for additional evaluation.
Many of the operations in these sheets are self-explanatory in nature, however a number of 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 if in case you have enabled them utilizing the Set-Mailbox PowerShell cmdlet. This operation is very similar to SearchQueryPerformed, besides it comprises 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 identify, standing, begin time, and finish time.
Replace—A message merchandise was up to date, together with metadata. One instance of that is when an electronic mail attachment is opened, which updates the metadata of the message merchandise and generates this occasion. An replace operation shouldn’t be all the time indicative of an electronic mail message being purposefully modified by a Risk Actor.
FileSyncDownloadedFull—Person establishes a sync relationship and efficiently downloads information for the primary time to their pc from a SharePoint or OneDrive for Enterprise doc library.
Detailed id and entry knowledge with Microsoft Entra
Our Microsoft Entra information covers actions which permit organizations to handle and defend their identities, knowledge, and units within the cloud. As an industry-leading id platform, Microsoft Entra ID provides superior security measures, corresponding to 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 function administration, machine registration, and listing synchronization to call a number of. To view detailed sign-in data, you should utilize the Signal-In Logs. The occasions situated in these two knowledge sources might help you detect and examine safety incidents, corresponding to unauthorized entry or configuration adjustments to the id aircraft.
You should use the next strategies to entry Microsoft Entra ID audit log knowledge:
Microsoft Entra Admin Portal—Go to the portal and sign up as an administrator. Navigate to Audit and/or Signal-ins below Monitoring. Filter, type, and export the information as wanted.
Azure AD PowerShell—Set up the Azure AD PowerShell module and hook up with Microsoft Entra ID. Use Get-AzureADAuditDirectoryLogs and/or Get-AzureADSignInLogs to get the information 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 knowledge (AuditLog.Learn.All and Listing.Learn.All). Use /auditLogs/directoryAudits and /auditLogs/signIns API endpoints to question the information, together with question parameters corresponding to $filter to refine the outcomes.
Many of the operations in these sheets are self-explanatory in nature, however as with our Microsoft 365 operations, a number of 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 comprises details about the reported sign-in—such because the consumer, the IP handle, the machine, the browser, the situation, and the chance degree. It additionally reveals the standing of the report—whether or not it was confirmed, dismissed, or ignored by the consumer or the administrator. This log occasion might 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—corresponding to creation, deletion, expiration, or renewal. Functions are often misused by Risk Actors to realize entry to knowledge, making this a essential administrative occasion if discovered throughout an investigation.
Any operation ending in ‘(bulk)’—These are attention-grabbing as they reveal a bulk exercise being carried out—corresponding to ‘Obtain customers’ or ‘Delete customers.’ Remember, nevertheless, 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 the moment logged-in id the Person Entry Administrator function 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 barely out there to customers who’re assigned the World Administrator function in Microsoft Entra ID. It may be utilized by Risk Actors to realize full management of Azure assets, 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 will probably be a worthwhile useful resource for you when you should shortly 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 keep in mind that the audit logs in Microsoft 365 and Microsoft Entra ID will not be the one supply of proof in a cloud-based case, and you must all the time correlate and validate your findings with different knowledge sources the place attainable.
To entry additional data on what knowledge lies in these logs and how one can entry them, reference the next weblog posts from the Microsoft Incident Response workforce:
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