Protecting your Teams with Azure Sentinel
Recent events have forced many organizations (including Microsoft) to move to a work from home model for their users. In order to ensure their users remain connected and productive they are turning to productivity tools such as Microsoft Teams to host meetings, allow teams to collaborate, and to help colleagues keep in touch. Moving to, or increasing usage of, Teams means that the service should be more of a focus for defenders than ever due to its critical role in communications and data sharing. In this blog we are going to focus on how we can collect Teams activity logs with Azure Sentinel, and start hunting for suspicious activity in that Teams data.Microsoft Sentinel API 101
Our Sentinel Management API just went GA! In this blog post we give you the 101 on the different APIs you can use to interact with Microsoft Sentinel. We'll look at how you can use them, when you should use them, what tools you can use to interact with them and how to authenticate to them.What’s New: Azure Sentinel Threat Hunting Enhancements
We are delighted to introduce a set of enhancements that greatly enhance the analyst experience with Azure Sentinel’s hunting capabilities by better tying them together, as well as by providing documentation and training on how to make the most of these existing capabilities.Monitoring Windows Virtual Desktop environments (Fall 2019 release) with Microsoft Sentinel
In order to enable remote work, some organizations have had to make rapid and sweeping changes to their endpoints. Windows Virtual Desktop (WVD) has enabled our customers to quickly provision Windows 10 virtual desktops to enable people who have traditionally not been remote workers to access a virtualized work desktop from home. However, these new endpoints also need to be monitored to maintain an organization’s security posture and so in this blog, we will explore how you can use Microsoft Sentinel to monitor your WVD environment.Protection Against Email Bombs with Microsoft Defender for Office 365
In today's digital age, email remains a critical communication tool for businesses and individuals. However, with the increasing sophistication of cyberattacks, email security has become more important than ever. One such threat that has been growing is the email bombing, a form of net abuse that sends large volumes of email to an address to overflow the mailbox, overwhelm the server, or distract attention from important email messages indicating a security breach. Email bomb - Wikipedia Understanding Email Bombing Email bombing, typically involves subscribing victims to a large number of legitimate newsletter and subscription services. Each subscription service sends email notifications, which in aggregate create a large stream of emails into the victim’s inbox, making email triage for legitimate emails very difficult. This form of attack is essentially a denial-of-service (DDOS) on the victim's email triaging attention budget. Hybrid Attacks More recently, email subscription bombs have been coupled with simultaneous lures on Microsoft Teams, Zoom, or via phone calls. Attackers impersonate IT support and offer to help solve the email problem caused by the spike of unwanted emails, ultimately compromising the victim's system or installing malware on their system. This type of attack is brilliant because it creates a sense of urgency and legitimacy, making victims more likely to accept remote assistance and inadvertently allow malware planting or data theft. Read about the use of mail bombs where threat actors misused Quick Assist in social engineering attacks leading to ransomware | Microsoft Security Blog. Incidence and Purpose of Email Bombing Email bombing attacks have been around for many years but can have significant impacts on targeted individuals, such as enterprise executives, HR or finance representatives. These attacks are often used as precursors to more serious security incidents, including malware planting, ransomware, and data exfiltration. They can also mute important security alerts, making it easier for attackers to carry out fraudulent activities without detection. New Detection technology for Mail Bombing attacks To address the limitations of current defenses which often include the victim’s attempt to build their own mail flow rules, Microsoft Defender for Office 365 releases a comprehensive solution involving a durable block to limit the influx of emails, majority of which are often Spam. By intelligently tracking message volumes across different sources and time intervals, this new detection leverages historical patterns of the sender and signals related to spam content. It prevents mail bombs from being dropped into the user’s inbox and the messages are rather sent to the Junk folder (of Outlook). Note: Safe sender lists in Outlook continue to be honored, so emails from trustworthy sources are not unexpectedly moved to the Junk folder (in order to prevent false positives). Since the initial rollout that started in early May, we’ve seen a tremendous impact in blocking mail bombing attacks out of our customers’ inboxes: How to leverage new “Mail bombing” detection technology in SOC experiences 1. Investigation and hunting: SOC analysts can now view the new Detection technology as Mail bombing within the following surfaces: Threat Explorer, Email entity page and Advanced Hunting empowering them to investigate, filter and hunt for threats related to mail bombing. 2. Custom detection rule: To analyze the frequency and volume of attacks from mail bombing vector, or to have automated alerts configured to notify SOC user whenever there is a mail bombing attack, SOC analysts can utilize the custom detection rules in Advanced hunting by writing a KQL query using data in DetectionMethods column of EmailEvents table. Here’s a sample query to get you started: EmailEvents | where Timestamp > ago(1d) | where DetectionMethods contains "Mail bombing" | project Timestamp, NetworkMessageId, SenderFromAddress, Subject, ReportId The SOC experiences are rolled out worldwide to all customers. Conclusion Email bombs represent an incidental threat in the world of cybersecurity. With the new detection technology for Mail Bombing, Microsoft Defender for Office 365 protects users from these attacks and empowers Security Operations Center Analysts to ensure to gain visibility into such attacks and take quick actions to keep organizations safe! Note: The Mail bombing protection is available by default in Exchange Online Protection and Microsoft Defender for Office 365 plans. This blog post is associated with Message Center post MC1096885. Also read Part 2 of our blog series to learn more about protection against multi-modal attacks involving mail bombing and correlation of Microsoft Teams activity in Defender. Learn: Detection technology details table What's on the Email entity page Filterable properties in the All email view in Threat Explorer
