Tag Archive: MDATP

Hunting for MiniNt security audit block in registry

Another day in the Advanced Hunting feature.

I was told about a twitter post which explained it’s possible to block Security events from being created.

If the following key is added:
HKLM\System\CurrentControlSet\Control\MiniNt

Event Viewer after the registry key was added and after a reboot

Since it’s registry we have a lot of data to query in the Defender ATP portal (https://securitycenter.windows.com)

The Hunting query will be as follows

// Mattias Borg
// @mattiasborg82
RegistryEvents 
| where (RegistryKey  == "HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\Control\\MiniNt") or
        (RegistryKey  == "HKEY_LOCAL_MACHINE\\SYSTEM\\ControlSet001\\Control\\MiniNt")
| sort by EventTime desc
| project EventTime, ComputerName, RegistryKey, InitiatingProcessAccountName, InitiatingProcessCommandLine, InitiatingProcessSHA1

This is the initial hunting query and might be changed to avoid False-Positives if there are any.

To be able to create a custom detection rule we need to add “MachineId” and “ReportId” to the output.

// Mattias Borg
// @mattiasborg82
RegistryEvents 
| where (RegistryKey  == "HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\Control\\MiniNt") or
        (RegistryKey  == "HKEY_LOCAL_MACHINE\\SYSTEM\\ControlSet001\\Control\\MiniNt")
| sort by EventTime desc
| project EventTime, ComputerName, RegistryKey, InitiatingProcessAccountName, InitiatingProcessCommandLine, InitiatingProcessSHA1, MachineId, ReportId 

Click on “Create a detection rule”

create detection rule

Fill in the form and select your preferred actions

defender atp custom rule

Happy Hunting!

Gartner EPP Magic quadrant 2019 – Defender in the leading quadrant

gartnereppmq2019

The 2019 version of the Gartner Magic Quadrant clearly shows that Microsoft is in the game to provide extremely powerfull Endpoint protection platform (EPP).
Microsoft is named a leader!

With built-in powerful capability which ties to Protect, Detect and respond, they have given us great tools for our security work.

Microsoft is unique in the EPP space, as it is the only vendor that can provide built-in endpoint protection capabilities tightly integrated with the OS. Windows Defender Antivirus (known as System Center Endpoint Protection in Window 7 and 8) is now a core component of all versions of the Windows 10 OS, and provides cloud-assisted attack protection.

Microsoft Defender Advanced Threat Protection (ATP) provides an EDR capability, monitoring and reporting on Windows Defender Antivirus and Windows Defender Exploit Guard (“Exploit Guard”), vulnerability and configuration management, as well as advanced hardening tools.

The Microsoft Defender ATP incident response console consolidates alerts and incident response activities across Microsoft Defender ATP, Office 365 ATP,
Azure ATP and Active Directory, as well as incorporates data sensitivity from Azure information protection.

Microsoft is much more open to supporting heterogeneous environments and has released EPP capabilities for Mac. Linux is supported through partners, while native agents are on the roadmap.

Microsoft has been placed in the Leaders quadrant this year due to the rapid market share gains of Windows Defender Antivirus (Defender), which is now the market share leader in business endpoints.

In addition, excellent execution on its roadmap make it a credible replacement for competitive solutions, particularly for organizations looking to reduce complexity.

Gartner

The benefit of the insights and protection these tools, and ability to use built-in SOAR capabilities, gives security teams around the globe a better and much faster understanding of the attacks for much fast response.

Many features like Exploit Protection, Network Protection, Attack Surface reduction, Firewall and more will provide a more reliable platform which is easy to manage.

The enriched alerts and incidents gives security teams a chance to put their effort to the critical incidents and avoid spending time trying to fight the noice in all different tools and manual tasks.

Automated investigations

Build your playbooks

Take back the control with live response

We also have the threat and vulnerability management feature which gives you visibility on vulnerable software in your estate

Threat hunting

Full gartner report:
https://www.gartner.com/doc/reprints?id=1-1OCBC1P5&ct=190731&st=sb&fbclid=IwAR3G9Otpxuc52bi0hpFE4-iGv8uhvgnxtSl0boqAU7-R4aw5MyLsuyy0fLg

Congratulations Microsoft, we’re looking forward for all coming features

Happy Hunting!

Hunting Windows Defender Exploit Guard with ATP

Alright, since I happen to be in a blog mode I keep the posts coming.

This post continue to explore the hunting capatibilities in Defender ATP by query for Exploit Guard detections.

So what’s this Exploit Guard?

Windows Defender Exploit Guard is a new set of intrusion prevention capabilities which are built-in with Windows 10, 1709 and newer versions.

Exploit Guard consists of 4 components which are designed to lock down the device against a wide variety of attack vectors and block behaviors commonly used in malware attacks, while enabling enterprises to balance their security risk and productivity requirements

ComponentDetails
Attack Surface Reduction (ASR)A set of controls that enterprises can enable to prevent malware from getting on the machine by blocking Office-, script-, and email-based threats
Network Protection Protects the endpoint against web-based threats by blocking any outbound process on the device to untrusted hosts/IP through Windows Defender SmartScreen
Controlled Folder AccessProtects sensitive data from ransomware by blocking untrusted processes from accessing your protected folders
Exploit ProtectionA set of exploit mitigations (replacing EMET) that can be easily configured to protect your system and applications

Example of ASR rules

• Block Office apps from creating executable content
• Block Office apps from launching child process
• Block Office apps from injecting into process
• Block Win32 imports from macro code in Office
• Block obfuscated macro code

Exploit Guard is configured through MDM (Intune) or SCCM or GPO’s or PowerShell.

If you have Microsoft 365 E5 license or Threat Protection license package, you don’t have to use Windows Event Forward to get the events in a central log solution. They will automatically be forwarded to your Microsoft 365 security portal https://security.microsoft.com where you have a nice looking dashboard where you can see alerts and configurations of ASR and other things.

This following dashboard is a part from the Monitor and Report section in the portal

Back to Defender ATP and the hunting which this post was supposed to be all about.

We have published some posts now about hunting custom alerts.

In the query console in Defender ATP we started to go backwards to find the ASR events. It’s simple. configure your client, run a few attacks which will trigger the alerts.

We looked in the MiscEvents for all events (filtered on computername and time). Which gaves us ideas of ActionTypes to use in the query.

Examples from the output:

AsrOfficeMacroWin32ApiCallsAudited
AsrPsexecWmiChildProcessBlocked
ControlledFolderAccessViolationBlocked
ExploitGuardAcgAudited
ExploitGuardChildProcessAudited
ExploitGuardNetworkProtectionBlocked
ExploitGuardNonMicrosoftSignedAudited
ExploitGuardWin32SystemCallBlocked
SmartScreenAppWarning
SmartScreenUrlWarning
SmartScreenUserOverride

Interesting note “SmartScreenUserOverride” is a separate event which you can query

When we had the raw Actiontypes we created the query to cover as much as we could.

//Happy Hunting
MiscEvents 
| where ActionType contains "asr" or
        ActionType contains "Exploit" or
        ActionType contains "SmartScreen" or
        ActionType contains "ControlledFolderAccess"
| extend JsonOut = parse_json(AdditionalFields)
| sort by EventTime desc 
| project EventTime, ComputerName, InitiatingProcessAccountName, ActionType,  
         FileName, FolderPath, RemoteUrl, ProcessCommandLine, InitiatingProcessCommandLine,
         JsonOut.IsAudit,JsonOut.Uri,JsonOut.RuleId,JsonOut.ActivityId
         

We are also parsing AdditionalFields to be able to add extra value to events which contained such data.

From this point we can do additional filters. For example, if you want to enable ASR enterprise wide, set them in auditmode and report on the alerts without affect user productivity, remediate and the do a enterprise wide block enrollment

Happy Hunting!

Automate response with Defender ATP and Microsoft Flow

So now when we have cool products (more or less builtin) we need to start working with them and not be required to look in the portals 24/7.

This post will demonstrate an example on how to use approval in email to isolate machines with new alerts.

Microsoft Flow is very easy to use to create business flows for all kind of products. You can manage anything which has an API.

Microsoft has released connectors for many solutions and by drag n drop you can create flows to make your life a lot easier.

This flow used in this blog post is just to be able to show something useful.

  • Start by browsing to https://flow.microsoft.com and create a new flow
  • Search for WDATP and select the Trigger “Triggers when a Windows Defender ATP alert accurs (preview)”

We will then add an action to “Get single alert preview”, this will give us more information to use later.

In below picture we can see some of the dynamic content we can add to next step in the flow

We can also add a condition. In this example we use condition for alert severity (high or medium).

We also want to add an approver step.

For some reason the Approval type is in Swedish for me. You have 2 default options and one custom option
Options are “Everyone must approve” or “First one to approve”.

Based on the response from the approval step we continue the flow with a condition to go ahead if the responder choose to approve the action.


We add the action “Isolate machine (preview)” and configure that along with a send email action.

Running the Flow

If you need to change your flow you can re-run it using the same data as used previously

After the approval we get the status message send to all approvers

We can see that our test machine was successfully isolated

In the flow test overview

From the ATP console we now have the option to release the machine from isolation, collect investigation package etc

Dynamic content

Actions

Pro tips:

  • Use get alert to be able to add more dynamic content to use in subsequent steps
  • Use get machine to be able to get more information like IP, Computername etc
  • Start building your automated playbooks. This will save you time