Detections

Explore public detection logic contributed by the community across SIEM and rule languages.

240 detections

Listing Email Remediation Actions performed via Explorer in Defender for Office 365
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
1043
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
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0042
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.
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
1040
This query was originally published in the threat analytics report, MailSniper Exchange attack tool.
MailSniper is a tool that targets Microsoft Exchange Server. The core function is to connect to Exchange Server and search through emails. In support of this, it can perform reconnaissance, collection, exfiltration, and credential theft. MailSniper is used both by red teams running penetration tests, and by malicious actors.
Microsoft Defender Security Center may record the following alerts during and after an attack:
1. Global mail search on Exchange using MailSniper
2. Exchange mailbox or mail folder search using MailSniper
3. Enumeration of Active Directory usernames using MailSniper
4. Enumeration of the Exchange GAL using MailSniper
5. Access to Exchange inboxes using MailSniper
6. Password spraying using MailSniper
7. Enumeration of domains and user accounts using MailSniper
The following query detects activity commonly associated with attacks run with MailSniper.
Reference - https://github.com/dafthack/MailSniper
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0039
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
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0038
'Identifies when multiple (more than one) users mailboxes are configured to forward to the same destination.
This could be an attacker-controlled destination mailbox configured to collect mail from multiple compromised user accounts.'
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
1035
This detection approach correlates a user accessing an email with image/document attachments and a risky sign-in attempt from non-trusted devices.
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0033
This query can be used to detect instances of a malicious insider creating a file archive and then emailing that archive to an external "competitor" organization.
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
1028
This query helps to find threats using display name impersonation for users not already protected with User Impersonation
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0028
This query checks devices for the presence of files that have been sent by a known malicious sender. To use this query, replace the email address with the address of the known malicious sender.
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
4027
Provides a summary of total number of detections
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
1025
Query for links opened from mail apps - if a detection occurred right afterwards.
As there are many links opened from mails, to have a successful hunt we should have some filter or join with some other signal,.
Such as suspicious processes, network connections, etc.
Therefore, in this example, we query for alerts that might be related to links sent via email.
This could be indicative of a phishing or spear-phishing attacks.
Tags: #EmailLink, #Phishing, #GetNearbyAlerts.
Explaining the underlying data:.
This query uses the BrowserLaunchedToOpenUrl event, that includes clicks on http:// or https:// links (clicks outside of browsers), or on .lnk files.
For this event, RemoteUrl contains the opened URL.
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
1024
This query graphs top accounts performing user submissions
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0024
This query visualises emails submitted by admins as false negatives, summarizing the data by top 10 sender domains of those emails
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0021
This query visualises the amount of emails subject to a user type policy with action of block, summarizing the data daily
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0021
This query visualises emails submitted by admins as false positives, summarizing the data by top 10 sender domains of those emails
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0020
This query helps hunting for top outbound recipient domains which are sending inbound emails with threats
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0019
In this detection,we hunt for emails with randomly named attachment names from the same sender to multiple recipients
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
1016
Total Submissions by Submission State
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0015
This query helps reviewing inbound / outbound / intra-org emails by domain per day
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0014
Total Submissions by Submission Type
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0013
Page 10 of 12