Microsoft Defender for Endpoint Windows 10\11 Roll Out Strategy Part 1

Microsoft Defender for Endpoint is a next generation XDR solution

Some of the items that really What sets Microsoft’s next generation XDR solution for endpoints ahead of alternative vendor XDR solutions are listed below.

  • 5 device licenses per user , Windows, Android, iOS, Linux, macOS
  • Defender to Endpoint integration with Defender for 365
  • Defender for Endpoint integration with Defender for Cloud Apps
  • Defender for Endpoint Web Filtering
  • Defender for Endpoint Vulnerability – Inventories , Recommendations, Weakness Reports, Event Time Lines
  • Advanced Hunting
  • Custom Detection Rules
  • Azure Sentinel integration
  • Protect internet facing devices
  • Intune integration
  • Automated investigation and remediation
  • Auto Isolation of devices that are classified as a high severity risk via Power Automate or Logic Apps
  • Power Automate approval workflow for isolation of medium severity risk devices
  • Cloud Security Analytics
  • Consult Threat experts
  • Initiate Live Response Session
  • Collect investigation package
  • Run antivirus scan
  • Restrict app execution
  • Isolate device
  • Contain device

    The Microsoft Security portal can provide advanced hunting KQL queries to assess the impact on an organisation’s newly configured security policies, prior to implementation.

An organisation should always improve the Microsoft Defender Vulnerability Management dashboard : exposure score, before choosing the auto remediation policy methods.

If there is an existing endpoint detection response solution, configure Microsoft Defender for Endpoint in EDR mode, to demonstrate all the vulnerabilities that the primary endpoint detection response solution does not report or remediate.

The next step will be to configure the automation remediation level to ‘Semi – require approval for core folders’, until Microsoft Defender for Endpoint, machine learning and cloud intelligence has, provided an organisation will all security and remediation metrics. Then ‘Full – remediate threats automatically’ can be enabled, and integrated with Microsoft Sentinel. SIEM without SOAR is useless.

Simply enabling ‘Full – remediate threats automatically’, may cause problems with certain applications. Every organisation is different and has different line of business applications.

In previous times, email, black and white lists were always implemented, the same way end point detection and response solutions, processes or folders were excluded from protection.

It is now recommended to configure as few exclusions as possible, with the advances in technologies like machine learning and AI. Machine learning and AI, can identify vulnerabilities that are unique to an organisation. The Microsoft Security Center processes more IT transactions daily and globally than any other security vendor in the world, and will most likely provide protection against zero day vulnerabilities than any other global security vendor.

No security vendor can claim to provide protection against a zero day vulnerability, however Microsoft Defender for Endpoint can dynamically provide protection, when analysing malicious behaviour via multiple methods like heuristic behaviour and are not dependent on security vulnerability signatures that have already been defined.

At the time of writing this blog, Microsoft Intune can provide the following amount of Microsoft Edge and Google Chrome configuration and control options.

#### Microsoft Edge

#### Google Chrome

Exchange 2016 – 2019 Federation Fails with Exchange Online

When attempting to federate a domain hosted in Exchange on premises with Exchange Online. The error message displayed below appears.

To resolve this issue TLS 1.2 needs to be enabled on the Exchange Hybrid servers.

ALI TAJRAN has a excellent ARTICLE and script to enable TLS 1.2 on Exchange servers. Once this script has run on the Exchange Hybrid servers, the wizard to add a federated domain will complete successfully.

Note: TLS 1.3 is not supported on Exchange on premises yet.

Microsoft Azure AD password protection Service vs Passwordless Authentication

When the Azure Active Directory Premium password protection service was first released, it was well received.

There a few issues with the Azure AD Premium ‘Password Protection’ service.

1: An enterprise customer will block internet access on all domain controllers
2: If using the Azure AD Premium ‘Password Protection’ service, it requires an agent installed on all domain controllers, this agent will then, communicate with a proxy agent to establish access to Azure AD. For example , ‘agent on dc’s’ communicates to agent on ‘AD Connect server’
3: Microsoft Defender for Identity domain controller agent, cannot co-exist with the Azure AD Premium ‘Password Protection’ service agent, on the same domain controller
4: Microsoft Defender for Identity service will significantly improve an organisation’s security posture in comparison to the Azure AD Premium ‘Password Protection’ service
5: A much easier and secure method of Identity Management, is to enable the Microsoft Active Directory Premium and Microsoft Authenticator services to use: Passwordless authentication.

Passwordless can protect against

BruteForce Attacks
Password Spray Attacks.

Enabling passwordless , can also help organisations, to get one step further in their Zero Trust journey

Securing M365 mail routing : SCENARIO 3

When an organisation has completely transitioned and migrated to Exchange Online and directed their MX record to contoso-com.mail.protection.outlook.com. The organisation should in line with best practices, have Microsoft Defender for Office365 Plan 2 securely configured.

Scenario 3, this my proffered choice. All Contoso *.onmicrosoft.com aliases can be blocked as they are no longer required. When Contoso’s mx record has been directed at Exchange Online protection. Exchange Online Protection & Microsoft Defender for 365 will protect all aliases. It may not even be necessary to block all Contoso *.onmicrosoft.com aliases.

It is possible to create an email address policy for Office365 groups that only use’s @contoso.com primary email addresses, which can still allow mail flow to Team’s channels. Then the usual protection of contoso.com comes into play, SPF, DKIM and finally DMARC.

Securing M365 mail routing : SCENARIO 2

Some organisations do not use Exchange Online Protection and Microsoft Defender for 365 to protect their Exchange Online tenant and use 3rd party message hygiene services like Mimecast and Proof Point. This blog will demonstrate a a scenario where securing Exchange Online message routing is configured incorrectly and could be classified a vulnerability,

SCENARIO 2


1. Contoso.com MX record is pointed at Mimecast; Mimecast provides spam protection
2. Mimecast then passes the messages to Exchange Online
3. If there are any remaining Exchange on-premise recipients, Exchange online will route the messages to the Exchange Hybrid servers via the secure Exchange Hybrid connectors
3. The Exchange Online inbound connector that accepts traffic from the Mimecast service is secured via TLS

VULNERABILITY
Anyone in the world can send an email to to an Exchange Online recipient with a *.mail.onmicrosoft.com or *.onmicrosoft.com alias, when sending to these domains. The messages completely bypasses , the organisation’s Mimecast’s message hygiene services and can route messages to Exchange Online recipients and Exchange on-premise recipients. If the organisation has not configured Exchange Online protection and Microsoft Defender for 365, then the organisation is vulnerable to malware and phishing emails.

Another problem: Office365 groups, When a Teams Channel is created, it creates an Office365 group that will have a *.onmicrosoft.com alias. Bad actors sending emails to these aliases can once again completely bypass the organisation’s message hygiene services.

SOLUTION
The Hybrid configuration wizard creates an Exchange Online inbound connector that is locked down with TLS via a public trusted certificate on the Exchange Hybrid servers.

The default inbound Exchange Online connector that was created by the Exchange Hybrid wizard, can be modified to only accept inbound messages from the IP ranges of the Mimecast service and TLS.

This script queries the existing inbound connector and creates an inbound connector that blocks messages recipients using the *.mail.onmicrosoft.com to only accept traffic from a service using the TLS certificate and connector that has been modified or it can query a new inbound connector

In this scenario , when a message is sent to an Exchange online recipient , the message flows as follows.
1. MX contoso.com
2. Mimecast
3. Contoso.com aliases & all consto.com *.onmicrosoft.com will only accept messages from Mimecast

Note: run this script using the latest Exchange Online PowerShell module

New-InboundConnector -Name ‘Restrict inbound mail flow to hybrid domains’ -ConnectorType Partner -SenderDomains * -TlsSenderCertificateName (Get-InboundConnector $InboundConnectorName).TlsSenderCertificateName -RestrictDomainsToCertificate $true -RequireTls $true