Detections

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

545 detections

This query helps hunting for Inbox rule changes which forward-redirect email
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
3048
'Identifies a match across various data feeds for domains, hashes and IP IOC related to Mercury
Reference: https://www.microsoft.com/security/blog/2022/08/25/mercury-leveraging-log4j-2-vulnerabilities-in-unpatched-systems-to-target-israeli-organizations/'
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0048
This query looks for users performing file deletion activities. Spikes in file deletion observed from risky sign-in sessions are flagged here.
This applies to SharePoint and OneDrive users.
Audit event and Cloud application identifier references.
Reference - https://learn.microsoft.com/microsoft-365/compliance/audit-log-activities?view=o365-worldwide
Reference - https://learn.microsoft.com/azure/sentinel/entities-reference#cloud-application-identifiers
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0046
Remote Monitoring and Management (RMM) programs are IT to manage remote endpoints. Attackers have begun to abuse these programs to persist or provide C2 channels.
https://github.com/jischell-msft/RemoteManagementMonitoringTools
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0047
Use this query to review OAuth applications whose behaviour has changed as compared to a prior baseline period. The following query returns OAuth Applications accessing user mail via Graph that did not do so in the preceding week.
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0045
Author: alex verboon @alexverboon.
Blogpost: https://www.verboon.info/2020/09/hunting-for-local-group-membership-changes.
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
7045
' The query below identifies creation of unusual identity by the Europium actor to mimic Microsoft Exchange Health Manager Service account using Exchange PowerShell commands
Reference: https://www.microsoft.com/security/blog/2022/09/08/microsoft-investigates-iranian-attacks-against-the-albanian-government/'
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
3042
This query shows all modifications to highly sensitive active directory groups (also known as Tier 0). An example of these groups include Domain Admins, Schema Admins and Enterprise Admins.
More info can be found here:
https://docs.microsoft.com/security/compass/privileged-access-access-model#evolution-from-the-legacy-ad-tier-model
https://docs.microsoft.com/windows-server/identity/ad-ds/plan/security-best-practices/appendix-c--protected-accounts-and-groups-in-active-directory
This advanced hunting query requires Defender for Identity be deployed due to it's reliance on the IdentityDirectoryEvents table.
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
5041
This query looks for identity add through exchange PowerShell
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0040
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
'This query looks for suspicious request patterns to Exchange servers that fit a pattern observed by Silk Typhoon actors.
The same query can be run on HTTPProxy logs from on-premise hosted Exchange servers.
Reference: https://www.microsoft.com/security/blog/2021/03/02/hafnium-targeting-exchange-servers/'
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0040
LemonDuck is an actively updated and robust malware primarily known for its botnet and cryptocurrency mining objectives. First discovered in 2019, LemonDuck has since adopted more sophisticated behavior and escalated its operations in 2021. Today, beyond using resources for its traditional bot and mining activities, LemonDuck steals credentials, removes security controls, spreads via emails, moves laterally, and ultimately drops more tools for human-operated activity.
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0038
This query was originally published in the threat analytics report, "Exchange Server zero-days exploited in the wild".
In early March 2021, Microsoft released patches for four different zero-day vulnerabilities affecting Microsoft Exchange Server. The vulnerabilities were being used in a coordinated attack. For more information on the vulnerabilities, visit the following links:
1. CVE-2021-26855
2. CVE-2021-26857
3. CVE-2021-26858
4. CVE-2021-27065
The following query finds evidence of a reverse shell being loaded using a technique associated with the Nishang penetration testing framework. This might indicate an attacker has remote access to the device.
More queries related to this threat can be found under the See also section of this page.
Reference - https://msrc-blog.microsoft.com/2021/03/02/multiple-security-updates-released-for-exchange-server/
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
1038
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
'Azure AD Connect (AAD Connect) is a critical service that handles connections between on-premise Active Directory and Azure AD.
Due to the critical nature of AAD Connect threat actors may attempt to compromise the service in order to access credentials.
This query looks for SSH connections to host that appear to run AAD Connect. The results should be reviewed to determine if the
SSH connection is legitimate.'
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0037
This query helps reviewing URL click count by ClickAction
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
1036
This query helps in reviewing top policies for user overrides (Allow/Block)
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0021
In this query, we are looking for Url clicks on emails which are generated the alert-A potentially malicious URL click was detected
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0035
This query finds the 10 latest logons performed by email recipients within 30 minutes after they received known malicious emails. You can use this query to check whether the accounts of the email recipients have been compromised.
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
3035
'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 query was originally published in the threat analytics report, CVE-2020-0601 certificate validation vulnerability.
The Windows CryptoAPI Spoofing Vulnerability, CVE-2020-0601, can be exploited to spoof code-signing certificates. For example, an attacker could forge a certificate that lists Microsoft as the issuer. This would allow an attacker to disguise a malicious executable as legitimate.
The vulnerability was patched with the January 2020 Security Update.
Use the following query to locate files containing ECC certificates that might have been forged using this vulnerability. The query identifies files that don't correctly identify the signer name, yet list Microsoft as the root signer.
References:
https://portal.msrc.microsoft.com/security-guidance/advisory/CVE-2020-0601
https://portal.msrc.microsoft.com/security-guidance/releasenotedetail/2020-Jan
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0034
Page 16 of 26