Protect your organizations against QR code phishing with Defender for Office 365
QR code phishing campaigns have most recently become the fastest growing type of email-based attack. These types of attacks are growing and embed QR code images linked to malicious content directly into the email body, to evade detection. They often entice unwitting users with seemingly genuine prompts, like a password reset or a two-factor authentication request. Microsoft Defender for Office 365 is continuously adapting as threat actors evolve their methodologies. In this blog post we’ll share more details on how we’re helping defenders address this threat and keeping end-users safe.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
Announcing quarantine release integration in Microsoft Defender for Office 365 hunting experience!!
This feature allows SecOps teams to define and better filter on messages with custom queries and take release action directly from hunting experiences - Threat Explorer, Advanced Hunting, Email summary panel, Email Entity Page, and custom detections!!
Build custom email security reports and dashboards with workbooks in Microsoft Sentinel
Security teams in both small and large organizations track key metrics to make critical security decisions and identify meaningful trends in their organizations. Defender for Office 365 has rich, built-in reporting capabilities that provide insights into your security posture to support these needs. However, sometimes security teams require custom reporting solutions to create dedicated views, combine multiple data sources, and get additional insights to meet their needs. We previously shared an example of how you can leverage Power BI and the Microsoft Defender XDR Advanced Hunting APIs to build a custom dashboard and shared a template that you can customize and extend. In this blog, we will showcase how you can use workbooks in Microsoft Sentinel to build a custom dashboard for Defender for Office 365. We will also share an example workbook that is now available and can be customized based on your organization’s needs. Why use workbooks in Microsoft Sentinel? There are many potential benefits to using workbooks if you already use Microsoft Sentinel and already stream the hunting data tables for Defender for Office 365: You can choose to store data for a longer period of time via configuring longer retention for tables you use for your workbooks. For example you can store Defender for Office 365 EmailEvents table data for 1 year and build visuals over longer period of time. You can customize your visuals easily based on your organization’s needs. You can configure auto-refresh for the workbook to keep the data shown up to date. You can access ready to use workbook templates and customize them if it's needed. Getting started After you connect your data sources to Microsoft Sentinel, you can visualize and monitor the data using workbooks in Microsoft Sentinel. Ensure that Microsoft Defender XDR is installed in your Microsoft Sentinel instance, so you can use Defender for Office 365 data with a few simple steps. Detection and other Defender for Office 365 insights are already available as raw data in the Microsoft Defender XDR advanced hunting tables: EmailEvents - contains information about all emails EmailAttachmentInfo - contains information about attachments in emails EmailUrlInfo - contains information about URLs in emails EmailPostDeliveryEvents – contains information about Zero-hour auto purge (ZAP) or Manual remediation events UrlClickEvents - contains information about Safe Links clicks from email messages, Microsoft Teams, and Office 365 apps in supported desktop, mobile, and web apps. CloudAppEvents – CloudAppEvents can be used to visualize user reported Phish emails and Admin submissions with Defender for Office 365. The Microsoft Defender XDR solution in Microsoft Sentinel provides a connector to stream the above data continuously into Microsoft Sentinel. Microsoft Sentinel then allows you to create custom workbooks across your data or use existing workbook templates available with packaged solutions or as standalone content from the content hub. How to access the workbook template We are excited to share a new workbook template for Defender for Office 365 detection and data visualization, which is available in the Microsoft Sentinel Content hub. The workbook is part of the Microsoft Defender XDR solution. If you are already using our solution, this update is now available for you. If you are installing the Microsoft Defender XDR solution for the first time, this workbook will be available automatically after installation. After the Microsoft Defender XDR solution is installed (or updated to the latest available version), simply navigate to the Workbooks area in Microsoft Sentinel and on the Templates tab select Microsoft Defender for Office 365 Detection and Insights. Using the “View Template” action loads the workbook. What insights are available in the template? The template has the following sections with each section deep diving into various areas of email security, providing details and insights to security team members: Detection overview Email - Malware Detections Email - Phish Detections Email - Spam Detections Email - Business Compromise Detections (BEC) Email - Sender Authentication based Detections URL Detections and Clicks Email - Top Users/Senders Email - Detection Overrides False Negative/Positive Submissions File - Malware Detections (SharePoint, Teams and OneDrive) Post Delivery Detections and Admin Actions Email - Malware Detections Email - Business Compromise Detections (BEC) Email - Sender Authentication based Detections URL Detections and Clicks False Negative/Positive Submissions File - Malware Detections (SharePoint, Teams and OneDrive) Post Delivery Detections and Admin Actions Can I customize the workbook? Yes, absolutely. Based on the email attributes in the Advanced Hunting schema, you can define more functions and visuals as needed. For example, you can use the DetectionMethods field to analyse detections caught by capabilities like Spoof detections, Safe Attachment, and detection for emails containing URLs extracted from QR codes. You can also bring other data sources into Microsoft Sentinel as tables and use them when creating visuals in the workbook. This sample workbook is a powerful showcase for how you can use the Defender for Office 365 raw detection data to visualize email security detection insights directly in Microsoft Sentinel. It enables organizations to easily create customized dashboards that can help them analyse, track their threat landscape, and respond quickly—based on unique requirements. Do you have questions or feedback about Microsoft Defender for Office 365? Engage with the community and Microsoft experts in the Defender for Office 365 forum. More information Integrate Microsoft Defender XDR with Microsoft Sentinel. Learn more about Microsoft Sentinel workbooks. Microsoft Defender for Office 365 Detection Details Report – Updated Power BI template for Microsoft Sentinel and Log Analytics Learn more about Microsoft Defender XDR.Submissions Response Using AI for Enhanced Result Explainability
We are pleased to announce that Microsoft Defender for Office 365 now features large language model (LLM)-powered responses within the submission workflow. This update provides security and Exchange admins with clear, actionable insights into the reasons behind the classification of each submission whether as spam, phishing, bulk, or clean - enabling more informed decision-making and response. What's new? Historically, submission results such as Threats found or No threats found have provided limited insight into the reasoning behind classification decisions. The implementation of AI-LLM-based responses addresses this limitation by delivering intuitive and context-rich explanations that clarify why a message was categorized as spam, phishing, bulk, or clean. This enhancement reduces ambiguity and facilitates faster, more accurate responses by administrators. LLM-based responses are now available for administrative email submissions made from any location within the Defender portal. Where can you see LLM based responses? Submissions page at https://security.microsoft.com/reportsubmission : On the Emails tab, select entry to view the LLM based explanation in the details flyout. Example- Example where submissions response came as clean- No threats found. The email is a simple and benign message with no malicious content or suspicious links. The sender and recipient both belong to the same domain (contoso.com), indicating internal communication. Interacting with this email poses no risk as it contains no harmful elements. Example where submissions response came as malicious- Threats found. The sender's email address (bad-vaibhav@contosoo.com) is suspicious and not associated with any legitimate organization. The email subject uses excessive promotional language and emojis, which is typical of spam emails. Interacting with the message could lead to unwanted advertisements or potential scams. Clicking on the provided link leads to a Contoso login page, which is a standard procedure for accessing internal resources. Key Result Types with LLM Support For the result types like Threats found, No threat found, Bulk, Spam and a few Unknowns, you will see the LLM-based explanation. However, if for any reason the AI-generated explanation is unavailable, the system will fall back to the existing explanation, ensuring continuity in the experience. Learn more: Check out our documentation for more details on submission workflows and AI-LLM based integration. Have feedback or questions about LLM based response? Join the conversation in the Microsoft Defender for Office 365 community forum.
