Detections

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

2,686 detections

Identify email exfiltration conducted by PowerShell.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
2028
'This hunting query looks for clients running queries that have not previously been seen running queries.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
1028
Original Sigma Rule: https://github.com/Neo23x0/sigma/blob/master/rules/apt/apt_judgement_panda_gtr19.yml.
Questions via Twitter: @janvonkirchheim.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0027
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
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AzureSentinel
1 year ago
0027
'Under specific circumstances, executing KQL queries can exfiltrate information like access tokens, regarding external data functions like adx().
This query tries to list executed KQL queries that used the adx() function and where an access token might have been exposed to.
Ref: https://docs.microsoft.com/azure/azure-monitor/logs/azure-monitor-data-explorer-proxy
Ref: https://securecloud.blog/2022/04/27/azure-monitor-malicious-kql-query/'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
1027
'This hunting query looks for users who are running multiple queries that return either a very large
amount of data or the maximum amount allowed by the query method.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
1026
'Alerts in links that have been shared across multiple Zoom chat channels by the same user in a short space if time.
Adjust the threshold figure to change the number of channels a message needs to be posted in before an alert is raised.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0026
The MailItemsAccessed action is part of the new Advanced Audit functionality of Microsoft Defender XDR. It's part of Exchange mailbox auditing and is enabled by default for users that have an Office 365 or Microsoft 365 E5 license, or for organizations with a Microsoft 365 E5 Compliance add-on subscription.
If more than 1,000 MailItemsAccessed audit records are generated in less than 24 hours, Exchange Online will stop generating auditing records for MailItemsAccessed activity. When a mailbox is throttled, MailItemsAccessed activity will not be logged for 24 hours after the mailbox was throttled. If this occurs, there's a potential that mailbox could have been compromised during this period. The recording of MailItemsAccessed activity will be resumed following a 24-hour period.
The query is looking for MailItemsAccessed Throttling events where the operation is done by a ClientApplication.
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
0024
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
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AzureSentinel
1 year ago
0024
'This hunting query looks for increases in the number of workspaces queried by a user.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
3023
'CreepyDrive uses OneDrive for command and control. This detection identifies URLs specific to CreepyDrive.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0023
This query monitors for users running Log Analytics queries that contain filters for specific, defined VIP user accounts or the VIPUser watchlist template.
Use this detection to alert for users specifically searching for activity of sensitive users.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
2023
'This hunting query looks for hosts that have attempted to interact with the Discord CDN. This activity is not normally invoked from the command line and could indicate C2, exfiltration, or malware delivery activity.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0022
'Looks for Base64-encoded commands associated with the Nishang reverse TCP shell.
Ref: https://github.com/samratashok/nishang/blob/master/Shells/Invoke-PowerShellTcp.ps1'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0022
This hunting query looks for hosts exporting a mailbox from an on-prem Exchange server, followed by
that same host removing the export within a short time window. This pattern has been observed by attackers
when exfiltrating emails from a target environment. A Mailbox export is unlikely to be a common command run so look for
activity from unexpected hosts and accounts.
Reference: https://www.volexity.com/blog/2020/12/14/dark-halo-leverages-solarwinds-compromise-to-breach-organizations/
Query insprired by Azure Sentinel detection https://github.com/Azure/Azure-Sentinel/blob/master/Hunting%20Queries/SecurityEvent/HostExportingMailboxAndRemovingExport.yaml
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
2022
This query can be used to detect instances of malicious users who attempt to create steganographic images and then immediately browse to a webmail URL. This query would require additional investigation to determine whether the co-occurrance of generating a steganographic image and browsing to a webmail URL is an indication of a malicious event.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
1021
'This hunting query looks for users whose total returned data that is significantly above their average.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0020
'This hunting query looks for users who have run queries that have not previously been seen running queries.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
1019
'This hunting query identifies GitHub activites where there are a large number of deletions that may be a sign of compromise.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
1018
'This hunting query looks for users who have run queries calling a watchlist template relating to sensitive data that have not previously been seen calling these watchlists.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0017
'The hunting query looks for suspicious files accessed on a IIS server that might indicate exfiltration hosting. This technique has been observed when exporting mailbox files from OWA servers.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0017
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