For most Microsoft products, data retention is 30 days. However, it depends on some products if you use the free or paid version of the product, and some products do not allow you to change to the retention period at all. To get a clear overview, I created a table with the most common Microsoft products with their retention period.
Not all products allow you to change the retention period, and some products come with an additional cost when changing the retention period. However, this is not always the case. When a Log Analytics Workspace is attached to Sentinel, data retention if free for 90 days.
Suppose you want to extend the retention period longer than the maximum period. In that case, you need to send the logs to a Security Information and Event Management (SIEM) solution or send it to an Azure Log Analytics workspace if the product supports it.
During an incident, you want to do your analysis as quickly and as precisely as possible. Although there are many scripts available to do proper research within Microsoft 365, if you are working with Exchange Online, OneDrive, SharePoint, they all need separate modules. Not to mention that Exchange Online sometimes need multiple modules depending on what data you want to extract. Using numerous modules can be a pain due to numerous logins that are required.
I wanted to create a ‘One ring to rule them all’ for any incident response within Microsoft 365, which is Operating System independent, runs natively on Windows, and works with or without Multi-Factor Authentication. PowerShell runs on Linux, macOS, natively on Windows, and it happens to be a language I somewhat understand.
Since many Microsoft security products and services connect to the Microsoft Graph Security API, I have chosen to use PowerShell in combination with the Microsoft Graph Security API.
To communicate to the Microsoft Graph Security API, you need an app registration. If you create an app registration, be sure you select the Microsoft graph and Application Permissions.
Note: During the application registration, write down the application ID, the client secret, and the tenant name.
The idea of answering a research question is to run a function, export the outcome to a JSON file, and filter the JSON file if needed. The sign-in logs, for example, contain a lot of information. Using your favorite tool, you can extract what research question you would like to answer. The export includes the location of the login. A simple query makes it possible to filter all logins outside the company’s country to get an overview of potential malicious logins.
The first thing you need to do is getting a token using the app registration you created previously.
Once you have a token, you can use the functions described below.
Note: The token expires in one hour. I have not had this issue myself that a function runs more than an hour, but I am looking to add a refresh token to the script. You can always request a new token described above, which is valid for another hour.
The first thing to look for is licenses. If the tenant contains an Office 365 Advanced Threat Protection license, it helps during the investigation. Or if the tenant contains an Azure AD Premium license, you know the logs in Azure AD go back one month instead of seven days.
I recommend starting with an output of the licenses to see what tools can help during the investigation.
Accepted domains are used in the tenant to sent and receive e-mail. The function RR-GetAcceptedDomains can extract all accepted domains within the tenant.
Getting all accepted domains is helpful to validate which domain names accept e-mail within the tenant.
Many attackers create inbox rules for persistence or hiding footprints. With the function RR-GetInboxRules you can export all inbox rules within the tenant or for a particular user.
The function RR-GetEmailBySubject searches for any e-mail with a given subject.
RR-GetEmailBySubject -subject "thalpius"
The function RR-GetEmailByBody searches for any e-mail with a given keyword in the body of the e-mail.
RR-GetEmailByBody -bodyKeyword "thalpius"
This function gives you the ability to extract all usernames with a given attachment filename in their mailbox.
RR-GetAttachment -fileName "thalpius.zip"
This function gives you the ability to extract attachments to check if it is malicious. It exports all attachments from a user’s mailbox or extracts the attachment itself if you use the attachmentId. The attachment is Base64 encoded. Decode the encoded string in the output to get the binary.
In an illicit consent grant attack, the attacker creates an Azure-registered application that requests access to data such as contact information and e-mail. This function exports all app registrations within the tenant, including the owner.
Every function adds the data to an array. Once you are done running all functions you think you need, RR-OutputArray creates a JSON file with all data. You can filter the data if needed using your favorite scripting language.
According to Microsoft, using Multi-Factor Authentication reduces 99,9% of account compromise attacks within Microsoft 365. Many companies know Multi-Factor Authentication is the right security solution, but what about other security measures?
Here are my top five security measures any company needs to take within Microsoft 365. I even made a downloadable infographic about it.
I want to start by saying that security awareness could easily be number one. I wanted to create a technical top five, but I can not miss out on security awareness as it is essential within any company.
Any given employee needs to be able to identify a threat. Security awareness training helps raise employees’ awareness to identify risks, and the employee then knows what to do when it comes to handling the threat or who to contact.
Security Operations Center
One of the most significant benefits of having a Security Operations Center (SOC) is twenty-four sevenmonitoring. Hackers do not have a nine to five mentality nor work from Monday till Friday. Is there a follow-up on a security threat on a Saturday at ten PM, or do you have to wait for employees to complain on Monday that they can not access their data due to ransomware? Monitoring your environment twenty-four seven is crucial within any company.
SPF, DKIM and DMARC
Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM), and Domain-based Message Authentication, Reporting, and Conformance (DMARC) are configurations to lower incoming phishing e-mail delivered in the inbox of the user. It is relatively easy to implement and does not come with additional costs. Since a lot of attacks use phishing, implementing SPF, DKIM, and DMARC is a must.
Multi-Factor Authentication and Legacy Authentication
Multi-Factor Authentication and Legacy Authentication go hand in hand since Legacy Authentication does not support Multi-Factor Authentication. So implementing Multi-Factor Authentication is not enough as Legacy Authentication should be disabled as well.
According to Microsoft, more than 99 percent of password spray attacks use legacy authentication protocols, and using Multi-Factor Authentication reduces 99,9% of the attacks within Microsoft Office 365.
In combination with secure awareness, Multi-Factor Authentication and disabling Legacy Authentication is a must within any Microsoft 365 environment.
There are many security measures a company can take. In my opinion, these are the five minimum Microsoft 365 security measures every company needs to take.
There are multiple ways to enable Multi-Factor Authentication (MFA) within Microsoft Office 365. This blog post will describe the various technical implementations of Multi-Factor Authentication, including the best-practice to implement it.
Azure AD MFA Per User
There are three Multi-Factor Authentication statuses within Microsoft Office 365: Enabled, Enforced, and Disabled. The status Enabled indicates that Multi-Factor Authentication is enabled, but the user did not go through the Multi-Factor Authentication registration yet. When the user goes through the Multi-Factor Authentication registration, the status changes to Enforced. Disabled means that Multi-Factor Authentication is not enabled, and the user does not have to log in with a Multi-Factor.
The risk by enabling Multi-Factor Authentication on a user-basis is misconfiguration since Multi-Factor Authentication is not enabled by default when creating a new user account. An administrator can forget enabling Multi-Factor Authentication, which increases the risk of a successful password attack due to missing Multi-Factor Authentication.
Azure AD MFA via Conditional Access
Conditional Access policies at their simplest are if-then statements; if a user wants to access a resource, then they must complete an action. An action can be Multi-Factor Authentication. With Conditional Access, you force every user to use Multi-Factor Authentication when logging into Microsoft Office 365. Using Conditional Access, the risk of misconfiguration lowers since every user applies to the Conditional Access when logging in, and its the best-practice to enable Multi-Factor Authentication.
Note: Azure AD Conditional Access is part of the Azure AD Premium licensing model. So additional costs are required.
Azure AD Named Locations
You can add trusted IP address ranges within Azure AD as Named Locations. A policy can then exclude the Named Locations. Using an exclusion can prevent an identity from being challenged with Multi-Factor Authentication if it comes from a trusted location.
Azure AD Identity Protection MFA Registration Policy
The advantage of using the Multi-Factor Authentication policy within Azure AD Identity Protection is that users have 14 days to complete the registration. During these 14 days, they can bypass registration, but they have to register before they can complete the sign-in process at the end of the period. Once the sign-in process is complete, the user can log in without Multi-Factor Authentication. The policy only forces a user to register Multi-Factor Authentication. The Azure AD Identity protection policy is unnecessary when Multi-Factor Authentication is enforced using Conditional Access.
Note: Azure AD Identity Protection is part of the Azure AD Premium licensing model. So additional costs are required.
Enabling this option configures your organization with the following settings:
Requiring all users to register for Azure Multi-Factor Authentication;
Requiring administrators to perform multi-factor authentication;
Blocking legacy authentication protocols;
Requiring users to perform multi-factor authentication when necessary;
Protecting privileged activities like access to the Azure portal.
Note: Azure AD Security Defaults are not suitable for complex security requirements. It is either turned on or turned off. If you want to make decisions based on a condition, Conditional Access is the way to go.
Microsoft Azure Active Directory supports several authentication and authorization protocols, including legacy authentication. Legacy authentication includes Exchange ActiveSync, SMTP, Autodiscover, Exchange Web Services, POP3, IMAP4, and many more.
The problem is, legacy authentication does not support Multi-Factor Authentication!
According to Microsoft, more than 99 percent of password spray attacks use legacy authentication protocols. It is crucial to disable legacy authentication when using Multi-Factor Authentication or in any situation.
You can use the Azure portal to identify the usage of legacy authentication within your environment before disabling it.
Navigate to; Azure portal > Azure Active Directory > Sign-ins.
Add the Client App column if it is not shown by clicking on; Columns > Client App.
Add filters > Client App > select all of the legacy authentication protocols. Select outside the filtering dialog box to apply your selections and close the dialog box.
Note: Conditional Access in Report-only mode is another way to identify legacy authentication within your environment.
According to Microsoft, using Multi-Factor Authentication reduces 99,9% of the attacks within Microsoft Office 365. Using Multi-Factor Authentication does not mean your company is safe for password attacks. It would not be the first time a user accepts a Multi-Factor Authentication challenge on their device when an attacker logs-in within Microsoft Office 365 with leaked credentials. So adoption and education for company users are critical. Enabling Multi-Factor Authentication and disabling legacy authentication is a minimum security measure every organization should take.
Microsoft Defender ATP is a fantastic product on its own and becomes even more impressive when integration between other Microsoft products takes place. This blog post will explain the advantages of integration with Microsoft Defender ATP and how the products complement each other.
Microsoft Defender ATP and Microsoft Office 365 ATP
Through threat intelligence sharing, a malicious attachment identified in Microsoft Office 365 ATP will be identified as malicious in Microsoft Defender ATP as well to block the same malicious file at the endpoint. A file downloaded using a different channel is blocked automatically on the endpoint due to integration between Microsoft Defender ATP and Microsoft Office 365 ATP.
Another advantage of the integration between Microsoft Defender ATP and Microsoft Office 365 ATP is an overview of devices shown that potentially could have been affected by a detected malicious e-mail message. The summary includes how many recent alerts those devices have in Microsoft Defender ATP.
The integration needs to be enabled in Microsoft Office 365 ATP and within Microsoft Defender ATP.
Note: Your organization must have Office 365 ATP Plan 2 and Microsoft Defender ATP.
Microsoft Defender ATP and Microsoft Azure ATP
A simple but powerful integration between Microsoft Defender ATP and Microsoft Azure ATP is the alerts shared between the two products.
The Microsoft Azure ATP portal shows Microsoft Defender ATP alerts, and the Microsoft Defender ATP portal shows Microsoft Azure ATP alerts.
The integration needs to be enabled in Microsoft Azure ATP and within Microsoft Defender ATP.
Microsoft Defender ATP and Azure AD Conditional Access
Microsoft Intune supports the integration between Microsoft Defender ATP and Azure AD Conditional Access.
If a device is non-compliant due to a Microsoft Intune policy, Conditional Access can block the device from accessing company data.
Microsoft Defender ATP and Azure Security Center
The integration between Microsoft Defender ATP and Azure Security Center Standard Tier automatically enables the Microsoft Defender ATP sensor for Windows Server 2008 R2 SP1, Windows Server 2012 R2, and Windows Server 2016 monitored by Azure Security Center. Windows Server is automatically on-boarded with integration enabled.
Alerts in Microsoft Defender ATP are shown in the Azure Security Center as well.
To integrate Microsoft Defender ATP with Azure Security Center, use the following option.
Microsoft Defender ATP and Skype for Business
A minor but helpful benefit of Skype for Business integration with Microsoft Defender ATP is a one-click communication with the user.
To integrate Microsoft Skype for Business with Microsoft Defender ATP, use the following option.
Microsoft Defender ATP and Microsoft Threat Protection
Microsoft Threat Protections and various Microsoft security solutions natively integrate Microsoft Defender ATP and other Microsoft security solutions. More on Microsoft Threat Protection in a future blog post.
This blog post is about integration with Microsoft Defender ATP alone. Integration with Microsoft Defender ATP has many benefits, as shown in this blog post. Imagine data correlation and integration between all Microsoft products.