Detections

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

24 detections

The following analytic detects the creation or deletion of Windows shares using the net.exe command. It leverages Endpoint Detection and Response (EDR) data to identify processes involving net.exe with actions related to share management. This activity is significant because it may indicate an attacker attempting to manipulate network shares for malicious purposes, such as data exfiltration, malware distribution, or establishing persistence. If confirmed malicious, this activity could lead to unauthorized access to sensitive information, service disruption, or malware introduction. Immediate investigation is required to determine the intent and mitigate potential threats.
Splunk Security@SplunkSecurity
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Splunk Security Content
16 days ago
000
This rule detects attempts to remove a network share connection using the 'NetUseDel' command. This activity is often associated with adversaries trying to hide their access or clean up traces after establishing persistence or performing other actions on a compromised system. The detection specifically looks for the 'NetUseDel' string within TCP traffic directed to port 445 (SMB/CIFS), indicating an attempt to delete a network share.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
001
Detects changes to the "MaxMpxCt" registry value.
MaxMpxCt specifies the maximum outstanding network requests for the server per client, which is used when negotiating a Server Message Block (SMB) connection with a client. Note if the value is set beyond 125 older Windows 9x clients will fail to negotiate.
Ransomware threat actors and operators (specifically BlackCat) were seen increasing this value in order to handle a higher volume of traffic.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
001
Detects when when a mounted share is removed. Adversaries may remove share connections that are no longer useful in order to clean up traces of their operation
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
000
Detects when when a mounted share is removed. Adversaries may remove share connections that are no longer useful in order to clean up traces of their operation
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
000
Administrative shares are hidden network shares created by Microsoft Windows NT operating systems that grant system administrators remote access to every disk volume on a network-connected system
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
000
Detects when a mounted network share is removed using PowerShell cmdlets such as 'Remove-SmbShare' or 'Remove-FileShare'. This activity can be an indicator of an adversary cleaning up traces of their operations.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0013
KQL Query from file: One-Click ANY RUN Storm-1747 KQL Scan
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Steven Lim@KQLWizard
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SlimKQL
1 year ago
5071
'This content is employed to correlate with Microsoft Defender XDR phishing-related alerts. It focuses on instances where a user successfully connects to a phishing URL from a non-Microsoft network device and subsequently makes successful sign-in attempts from the phishing IP address.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
5095
Detects changes to the "MaxMpxCt" registry value.
MaxMpxCt specifies the maximum outstanding network requests for the server per client, which is used when negotiating a Server Message Block (SMB) connection with a client. Note if the value is set beyond 125 older Windows 9x clients will fail to negotiate.
Ransomware threat actors and operators (specifically BlackCat) were seen increasing this value in order to handle a higher volume of traffic.
Yamato Security Hayabusa@YamatoSecurityHayabusa
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Yamato Security Hayabusa Rules
1 year ago
0012
Administrative shares are hidden network shares created by Microsoft Windows NT operating systems that grant system administrators remote access to every disk volume on a network-connected system
Yamato Security Hayabusa@YamatoSecurityHayabusa
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Yamato Security Hayabusa Rules
1 year ago
0010
Detects when when a mounted share is removed. Adversaries may remove share connections that are no longer useful in order to clean up traces of their operation
Yamato Security Hayabusa@YamatoSecurityHayabusa
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Yamato Security Hayabusa Rules
1 year ago
0010
Baseline Comparison.
Author: miflower.
The purpose of this query is to perform a comparison between "known good" machines and suspected bad machines.
The original concept for this query was born due to reapplying the same 'whitelist' filters over and over.
It brings deltas between a baseline and another machine quickly to the analyst's view.
This query supports multiple suspected bad machines and multiple "known good" machines.
It also supports providing a timeframe for how far back in time to build a baseline as well as how far back in time to evaluate the suspected bad machines.
Each of the links provided by DeviceId/DeviceName will go to the most recent entry for whatever entity is listed.
Average results for the pre-defined settings below with a single good host and a single bad host on a 'huge' tenant (300k+ machines):.
Compute Time: ~10-20 seconds.
Result Set Size: ~500 rows.
The workflow is as follows:.
1. Establish Variables that are editable on a per-query basis.
2. Define functions for reuse.
3. Calculate DeviceIds for all machines in scope.
4. Derive deltas using the aforementioned functions.
5. Union together all results into a single view.
The following datasets are returned:.
1. Alerts on the suspected bad machines (ignores known good machines, because...they're alerts, additional data has the triggered file).
2. Connected Networks (from DeviceNetworkInfo table, additional data has full Connected Network details).
3. File Creations (disabled by default due to volume, enable at your own risk, additional data has initiating processes).
4. Image Loads (disabled by default due to volume, enable at your own risk, additional data has initiating processes).
5. Logon (derived from DeviceLogonEvents for the unique users logged on, additional data has logon types).
6. Network communication (grouped by 2nd level-domain, ie 'microsoft.com' in 'www.microsoft.com' and 'web.microsoft.com', additional data has the full list of URLs).
7. Process creation (additional da
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
8168
Detects when when a mounted share is removed. Adversaries may remove share connections that are no longer useful in order to clean up traces of their operation
Yamato Security Hayabusa@YamatoSecurityHayabusa
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Yamato Security Hayabusa Rules
1 year ago
007
Query 1 shows you any network communication happened from endpoints to a specific Remote IP or Remote URL.
Ensure to update RemoteIP and RemoteURL variable.
For questions @MiladMSFT on Twitter or milad.aslaner@microsoft.com by email.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
5137
Detects changes to the "MaxMpxCt" registry value.
MaxMpxCt specifies the maximum outstanding network requests for the server per client, which is used when negotiating a Server Message Block (SMB) connection with a client. Note if the value is set beyond 125 older Windows 9x clients will fail to negotiate.
Ransomware threat actors and operators (specifically BlackCat) were seen increasing this value in order to handle a higher volume of traffic.
Yamato Security Hayabusa@YamatoSecurityHayabusa
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Yamato Security Hayabusa Rules
1 year ago
006
Device Network Events Involving Low Count FQDNs.
This query reduces network events to only those with the RemoteURL column populated,.
Then parses the DNS name from the URL (if needed) and finds the least prevalent.
FQDNs. The result is then joined with DeviceNetworkEvents to highlight anomalous.
Network communication.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0031
Detects when when a mounted share is removed. Adversaries may remove share connections that are no longer useful in order to clean up traces of their operation
Yamato Security Hayabusa@YamatoSecurityHayabusa
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Yamato Security Hayabusa Rules
1 year ago
004
Administrative shares are hidden network shares created by Microsoft Windows NT operating systems that grant system administrators remote access to every disk volume on a network-connected system
Yamato Security Hayabusa@YamatoSecurityHayabusa
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Yamato Security Hayabusa Rules
1 year ago
004
Query 1 shows you any network communication happened from endpoints to a specific Remote IP or Remote URL.
Ensure to update RemoteIP and RemoteURL variable.
For questions @MiladMSFT on Twitter or milad.aslaner@microsoft.com by email.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0021
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
1017
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