Detections
Explore public detection logic contributed by the community across SIEM and rule languages.
233 detections
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This query visualises top outbound recipient domains by outbound email volume and shows total number of inbound emails with Threats from the same domains (as inbound senders)
This query visualises user submissions where admin also performed 'mark and notify' action on the submission
Detects adding and using Exchange PowerShell snap-ins to export mailbox data. As seen used by HAFNIUM and APT27
Detects adding and using Exchange PowerShell snap-ins to export mailbox data. As seen used by HAFNIUM and APT27
'This query helps detect new Microsoft Entra ID sign in from a new location correlating with Office Activity data highlighting cases where user mails are being forwarded and shows if it is being forwarded to external domains as well.'
Hacktool Ruler
Sigma
This events that are generated when using the hacktool Ruler by Sensepost
'It is possible that a disabled user account is compromised and another account on the same IP is used to perform operations that are not typical for that user.
The query filters the SigninLogs for entries where ResultType is indicates a disabled account and the TimeGenerated is within a defined time range.
It then summarizes these entries by IPAddress and AppId, calculating various statistics such as number of login attempts, distinct UPNs, App IDs etc and joins these results with another set of results from SigninLogs, filtering for entries with less than normal number of successful sign-ins.
It then filters out entries where there were no successful sign-ins or where successful sign-ins did not occur within the same lookback period as the failed sign-ins, later projecting relevant fields by the count of login attempts, and expands the set of successful sign-ins into individual events.
Finally, it joins these results with entries from OfficeActivity where certain operations deemed rare and high risk have been performed, ensuring their occurrance within a certain time range of the successful sign-ins.'
The query filters the SigninLogs for entries where ResultType is indicates a disabled account and the TimeGenerated is within a defined time range.
It then summarizes these entries by IPAddress and AppId, calculating various statistics such as number of login attempts, distinct UPNs, App IDs etc and joins these results with another set of results from SigninLogs, filtering for entries with less than normal number of successful sign-ins.
It then filters out entries where there were no successful sign-ins or where successful sign-ins did not occur within the same lookback period as the failed sign-ins, later projecting relevant fields by the count of login attempts, and expands the set of successful sign-ins into individual events.
Finally, it joins these results with entries from OfficeActivity where certain operations deemed rare and high risk have been performed, ensuring their occurrance within a certain time range of the successful sign-ins.'
This query helps to hunt for possible email bombing attacks in Microsoft Defender for Office 365.
In this query, we are looking for emails containing malware accessed on a unmanaged device
This query looks for anomalies in mail item access events made by Graph API. It uses standard deviation to determine if the number of events is anomalous. The query returns all clientIDs where the amount of mail sent per day was larger than value given by the formula, 'average + STDThreshold(2.5)*(standard deviation)'.
See The MailItemsAccessed mailbox auditing action.
Reference - https://docs.microsoft.com/microsoft-365/compliance/mailitemsaccessed-forensics-investigations?view=o365-worldwide#the-mailitemsaccessed-mailbox-auditing-action
See The MailItemsAccessed mailbox auditing action.
Reference - https://docs.microsoft.com/microsoft-365/compliance/mailitemsaccessed-forensics-investigations?view=o365-worldwide#the-mailitemsaccessed-mailbox-auditing-action
Intent:
- Use MTP capability to look for insider threat potential risk indicators
- Indicators would then serve as the building block for insider threat risk modeling in subsequent tools
Definition of Insider Threat:
"The potential for an individual who has or had authorized access to an organization's assets to use their access, either maliciously or unintentionally, to act in a way that could negatively affect the organization."
This collection of queries describes the different indicators that could be used to model and look for patterns suggesting an increased risk of an individual becoming a potential insider threat.
Note: no single indicator should be used as a lone determinant of insider threat activity, but should be part of an overall program to understand the increased risk to your organization's critical assets. This in turn is used to feed an investigation by a formal insider threat program to look at the context associated with the whole person to understand the implication of a set of indicators.
- Use MTP capability to look for insider threat potential risk indicators
- Indicators would then serve as the building block for insider threat risk modeling in subsequent tools
Definition of Insider Threat:
"The potential for an individual who has or had authorized access to an organization's assets to use their access, either maliciously or unintentionally, to act in a way that could negatively affect the organization."
This collection of queries describes the different indicators that could be used to model and look for patterns suggesting an increased risk of an individual becoming a potential insider threat.
Note: no single indicator should be used as a lone determinant of insider threat activity, but should be part of an overall program to understand the increased risk to your organization's critical assets. This in turn is used to feed an investigation by a formal insider threat program to look at the context associated with the whole person to understand the implication of a set of indicators.
'This script identifies rare domain accounts accessing cloud resources by examining logs. You can lower the domainLimit value to see domains with fewer access attempts. For example, set domainLimit = 2 to see domains with 2 or fewer access attempts.'
This query helps hunting for Inbox rule changes which forward-redirect email
Listing Email Remediation Actions performed via Explorer in Defender for Office 365
'Any Alerts that fired related to a given IpAddress during the range of +6h and -3d'
This query will find applications that have been granted Mail.Read or Mail.ReadWrite permissions in which the corresponding user recently consented to. It can help identify applications that have been abused to gain access to user email.
The actor, Nobelium, was observed modifying existing tenant application permissions to allow them to read user email through the Microsoft Graph API. See Customer Guidance on Recent Nation-State Cyber Attacks.
This query is insprired by an Azure Sentinel detection.
References:
https://msrc-blog.microsoft.com/2020/12/13/customer-guidance-on-recent-nation-state-cyber-attacks/
https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/MailPermissionsAddedToApplication.yaml
The actor, Nobelium, was observed modifying existing tenant application permissions to allow them to read user email through the Microsoft Graph API. See Customer Guidance on Recent Nation-State Cyber Attacks.
This query is insprired by an Azure Sentinel detection.
References:
https://msrc-blog.microsoft.com/2020/12/13/customer-guidance-on-recent-nation-state-cyber-attacks/
https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/MailPermissionsAddedToApplication.yaml
This query looks for users accessing multiple other users' mailboxes, or accessing multiple folders in another user's mailbox.
This query is inspired by an Azure Sentinel detection.
Reference - https://github.com/Azure/Azure-Sentinel/blob/master/Hunting%20Queries/OfficeActivity/AnomolousUserAccessingOtherUsersMailbox.yaml
This query is inspired by an Azure Sentinel detection.
Reference - https://github.com/Azure/Azure-Sentinel/blob/master/Hunting%20Queries/OfficeActivity/AnomolousUserAccessingOtherUsersMailbox.yaml
Intent:
- Use MTP capability to look for insider threat potential risk indicators
- Indicators would then serve as the building block for insider threat risk modeling in subsequent tools
Definition of Insider Threat:
"The potential for an individual who has or had authorized access to an organization's assets to use their access, either maliciously or unintentionally, to act in a way that could negatively affect the organization."
This collection of queries describes the different indicators that could be used to model and look for patterns suggesting an increased risk of an individual becoming a potential insider threat.
Note: no single indicator should be used as a lone determinant of insider threat activity, but should be part of an overall program to understand the increased risk to your organization's critical assets. This in turn is used to feed an investigation by a formal insider threat program to look at the context associated with the whole person to understand the implication of a set of indicators.
- Use MTP capability to look for insider threat potential risk indicators
- Indicators would then serve as the building block for insider threat risk modeling in subsequent tools
Definition of Insider Threat:
"The potential for an individual who has or had authorized access to an organization's assets to use their access, either maliciously or unintentionally, to act in a way that could negatively affect the organization."
This collection of queries describes the different indicators that could be used to model and look for patterns suggesting an increased risk of an individual becoming a potential insider threat.
Note: no single indicator should be used as a lone determinant of insider threat activity, but should be part of an overall program to understand the increased risk to your organization's critical assets. This in turn is used to feed an investigation by a formal insider threat program to look at the context associated with the whole person to understand the implication of a set of indicators.
In this query, we hunt for inbound emails having URLs from QR codes and send by non-prevalent senders
Identifies anomalous increases in Exchange mail items accessed operations.
The query leverages KQL built-in anomaly detection algorithms to find large deviations from baseline patterns.
Sudden increases in execution frequency of sensitive actions should be further investigated for malicious activity.
Manually change scorethreshold from 1.5 to 3 or higher to reduce the noise based on outliers flagged from the query criteria.
Read more about MailItemsAccessed- https://docs.microsoft.com/microsoft-365/compliance/advanced-audit?view=o365-worldwide#mailitemsaccessed
Query insprired by Azure Sentinel detection https://github.com/Azure/Azure-Sentinel/blob/master/Detections/OfficeActivity/MailItemsAccessedTimeSeries.yaml
The query leverages KQL built-in anomaly detection algorithms to find large deviations from baseline patterns.
Sudden increases in execution frequency of sensitive actions should be further investigated for malicious activity.
Manually change scorethreshold from 1.5 to 3 or higher to reduce the noise based on outliers flagged from the query criteria.
Read more about MailItemsAccessed- https://docs.microsoft.com/microsoft-365/compliance/advanced-audit?view=o365-worldwide#mailitemsaccessed
Query insprired by Azure Sentinel detection https://github.com/Azure/Azure-Sentinel/blob/master/Detections/OfficeActivity/MailItemsAccessedTimeSeries.yaml
Credentials were added to an application by UserA, after the application was granted admin consent rights by UserB
The Nobelium activity group has been observed adding credentials (x509 keys or password credentials) for one or more legitimate OAuth Applications or Service Principals, usually with existing Mail.Read or Mail.ReadWrite permissions, which grants the ability to read mail content from Exchange Online via Microsoft Graph or Outlook REST. Examples include mail archiving applications.
See Customer Guidance on Recent Nation-State Cyber Attacks for more on the Nobelium campaign (formerly known as Solorigate).
See Grant tenant-wide admin consent to an application for how to add admin consent to an application.
More Nobelium-related queries can be found listed under the See also section of this document.
References:
https://msrc-blog.microsoft.com/2020/12/13/customer-guidance-on-recent-nation-state-cyber-attacks/
https://docs.microsoft.com/azure/active-directory/manage-apps/grant-admin-consent
The Nobelium activity group has been observed adding credentials (x509 keys or password credentials) for one or more legitimate OAuth Applications or Service Principals, usually with existing Mail.Read or Mail.ReadWrite permissions, which grants the ability to read mail content from Exchange Online via Microsoft Graph or Outlook REST. Examples include mail archiving applications.
See Customer Guidance on Recent Nation-State Cyber Attacks for more on the Nobelium campaign (formerly known as Solorigate).
See Grant tenant-wide admin consent to an application for how to add admin consent to an application.
More Nobelium-related queries can be found listed under the See also section of this document.
References:
https://msrc-blog.microsoft.com/2020/12/13/customer-guidance-on-recent-nation-state-cyber-attacks/
https://docs.microsoft.com/azure/active-directory/manage-apps/grant-admin-consent
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