Detections

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

13 detections

'The query looks for source code files being modified immediately after a build process is started. The purpose of this is to look for malicious code injection during the build process.
More details: https://techcommunity.microsoft.com/t5/azure-sentinel/monitoring-the-software-supply-chain-with-azure-sentinel/ba-p/2176463'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
2075
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
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0051
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
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AzureSentinel
1 year ago
0045
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
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AzureSentinel
1 year ago
0042
This query will find when a new credential is added to an application or service principal.
The Nobelium activity group was able to gain sufficient access to add credentials to existing applications with mail read permissions. They used that access to exfiltrate email.
See Customer Guidance on Recent Nation-State Cyber Attacks for more on the Nobelium campaign (formerly known as Solorigate).
Additional information on OAuth Credential Grants can be found in RFC 6749 Section 4.4 or Microsoft Entra ID audit activity reference.
For further information on AuditLogs please see Microsoft Entra ID audit activity reference.
This query was inspired by an Azure Sentinel detection.
References:
https://msrc-blog.microsoft.com/2020/12/13/customer-guidance-on-recent-nation-state-cyber-attacks/
https://docs.microsoft.com/azure/active-directory/develop/v2-oauth2-client-creds-grant-flow
https://docs.microsoft.com/azure/active-directory/reports-monitoring/reference-audit-activities
https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/NewAppOrServicePrincipalCredential.yaml
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
1041
Attackers can use Adfind which is administrative tool to gather information about Domain controllers, ADFS Servers. They may also rename executables with other benign tools on the system.
Below query will look for adfind usage in commandline arguments irrespective of executable name in short span of time. You can limit query this to your DC and ADFS servers.
Below references talk about suspicious use of adfind by adversaries.
- https://thedfirreport.com/2020/05/08/adfind-recon/
- https://www.fireeye.com/blog/threat-research/2020/05/tactics-techniques-procedures-associated-with-maze-ransomware-incidents.html
- https://www.microsoft.com/security/blog/2020/12/18/analyzing-solorigate-the-compromised-dll-file-that-started-a-sophisticated-cyberattack-and-how-microsoft-defender-helps-protect/
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0038
As described in previous guidance, Nobelium may re-purpose legitimate existing OAuth Applications in the environment to their own ends. However, malicious activity patterns may be discernable from legitimate ones.
The following query returns OAuth Applications that access mail both directly and via Graph, allowing review of whether such dual access methods follow expected use patterns.
Reference - https://msrc-blog.microsoft.com/2020/12/13/customer-guidance-on-recent-nation-state-cyber-attacks/
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
1035
To evade security software and analyst tools, Nobelium malware enumerates the target system looking for certain running processes, loaded drivers, and registry keys, with the goal of disabling them.
The Microsoft Defender for Endpoint sensor is one of the processes the malware attempts to disable.
Microsoft Defender for Endpoint has built-in protections against many techniques attackers use to disable endpoint sensors ranging from hardened OS protection, anti-tampering policies, and detections for a variety of tampering attempts, including "Attempt to stop Microsoft Defender for Endpoint sensor", "Tampering with Microsoft Defender for Endpoint sensor settings", or "Possible sensor tampering in memory".
Successfully disabling Microsoft Defender for Endpoint can prevent the system from reporting observed activities.
However, the multitude of signals reported into Microsoft Defender XDR provides a unique opportunity to hunt for systems where the tampering technique used might have been successful.
The following advanced hunting query can be used to locate devices that should be reporting but aren't:
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0034
Search for the files that are using a compromised certificate associated with the Nobelium campaign.
You can remove the comments to:
1. get the list of devices where there is at least one file signed with the certificate
2. get the list of files signed with the certificate
3. get the list of files signed with the certificate group by Devices
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0031
This query was originally published in the threat analytics report, Solorigate supply chain attack. Please note that these attacks are currently known as the Nobelium campaign.
Microsoft detects the 2020 SolarWinds supply chain attack implant and its other components as part of a campaign by the Nobelium activity group. Nobelium is the threat actor behind the attack against SolarWinds, which was previously referred to as Solorigate.
Nobelium silently added malicious code to legitimate software updates for Orion, which is IT monitoring software provided by SolarWinds. In this way, malicious dynamic link libraries (DLLs) were distributed to SolarWinds customers.
The following query locates malicious Nobelium-associated DLLs that have been loaded into memory on affected systems.
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://www.microsoft.com/security/blog/2020/12/18/analyzing-solorigate-the-compromised-dll-file-that-started-a-sophisticated-cyberattack-and-how-microsoft-defender-helps-protect/
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0026
This query searches for the HASHs of the FireEye Red Team tools compromised by the Nobelium activity group.
See all-hashes.csv on the official FireEye repo.
References:
https://github.com/fireeye/red_team_tool_countermeasures/blob/master/all-hashes.csv
https://github.com/fireeye
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0017
'This detection uses Security events from the "AD FS Auditing" provider to detect suspicious object identifiers (OIDs) as part EventID 501 and specifically part of the Enhanced Key Usage attributes.
This query checks to see if you have any new OIDs in the last hour that have not been seen in the previous day. New OIDs should be validated and OIDs that are very long, as indicated
by the OID_Length field, could also be an indicator of malicious activity.
In order to use this query you need to enable AD FS auditing on the AD FS Server.
References:
https://www.microsoft.com/security/blog/2022/08/24/magicweb-nobeliums-post-compromise-trick-to-authenticate-as-anyone/
https://docs.microsoft.com/windows-server/identity/ad-fs/troubleshooting/ad-fs-tshoot-logging
'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
2015
This query was originally published in the threat analytics report, Solorigate supply chain attack. Please note that these attacks are currently known as the Nobelium campaign.
Microsoft detects the 2020 SolarWinds supply chain attack implant and its other components as part of a campaign by the Nobelium activity group. Nobelium is the threat actor behind the attack against SolarWinds, which was previously referred to as Solorigate.
Nobelium silently added malicious code to legitimate software updates for Orion, which is IT monitoring software provided by SolarWinds. In this way, malicious dynamic link libraries (DLLs) were distributed to SolarWinds customers.
The following query retrieves an inventory of SolarWinds Orion software use in your organization, organized by product name and ordered by how many devices the software is installed on.
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://www.microsoft.com/security/blog/2020/12/18/analyzing-solorigate-the-compromised-dll-file-that-started-a-sophisticated-cyberattack-and-how-microsoft-defender-helps-protect/
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0012