Detections

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

747 detections

Detects attempts to disable or tamper with Windows Defender settings, services, or registry keys via command-line execution (such as reg.exe, PowerShell, or sc.exe) or direct registry modifications.
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ills3c Intel&Coffee@Ills3C
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Detections.ai Community
6 days ago
6014
Detects a sequence where a Codex agent process executes a shell or command interpreter, followed by logging or monitoring tampering activity on the same device within a 30-minute window.
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ills3c Intel&Coffee@Ills3C
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Detections.ai Community
1 day ago
003
Detects the addition of Microsoft Defender exclusions targeting the C:\Windows directory or SystemHealth\Update paths via PowerShell commands (Add-MpPreference/Set-MpPreference) or direct Registry modifications, which may indicate an attempt to evade security detection.
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ills3c Intel&Coffee@Ills3C
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Detections.ai Community
3 days ago
205
Detects potential defense evasion activity where Windows Defender configurations are modified or disabled, followed closely within 20 minutes by a silent, quiet, or unattended software uninstallation initiated by a script interpreter or command processor on the same device.
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ills3c Intel&Coffee@Ills3C
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Detections.ai Community
5 days ago
002
Detects the execution of the hacktool Defendnot. Defendnot is a hacktool that abuses Microsoft undocumented WSC (Windows Security Center) API
to disable Windows Defender by registering itself as a fake antivirus product. Threat actors often use these kind of tools to bypass security measures.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
10 days ago
204
Detects Java processes spawning PowerShell or Command Prompt to modify Windows Defender settings by adding exclusions for sensitive paths or extensions (such as AppData, Temp, Users Public, or ProgramData).
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ills3c Intel&Coffee@Ills3C
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Detections.ai Community
13 days ago
108
Detects the default scheduled task activity of the hacktool Defendnot, which is used to disable Windows Defender Security.
It abuses Microsoft's undocumented WSC API to register itself as a fake antivirus product, allowing it to disable Windows Defender.
During installation, Defendnot creates a scheduled task named 'defendnot' with the argument '--from-autorun' for persistence.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
10 days ago
103
Detects execution of Defendnot installation via PowerShell one-liner that downloads and executes the Defendnot script from a remote URL.
Defendnot is a hacktool that abuses Microsoft's undocumented WSC API to disable Windows Defender by registering itself as a fake antivirus product.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
10 days ago
003
Detects the usage of binaries such as 'net', 'sc' or 'powershell' in order to stop, pause, disable or delete critical or important Windows services such as AV, Backup, etc. As seen being used in some ransomware scripts
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
12 days ago
005
Detects potential defense evasion activity where Windows Defender configurations are modified or disabled, followed closely within 20 minutes by a silent, quiet, or unattended software uninstallation initiated by a script interpreter or command processor on the same device.
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ills3c Intel&Coffee@Ills3C
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Detections.ai Community
5 days ago
000
Detects modification of the Microsoft Security Center AV registry keys, particularly those related with DisplayName, ProductEXE, or ReportingExe.
These keys typically store information about antivirus products installed on the system, which is Windows Defender or third-party antivirus software.
But, if these keys holds unexpected values or are modified in a suspicious manner, it could indicate an attempt to tamper with the security settings of the system.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
10 days ago
001
Detects command line activity that tries to clear or disable any ETW trace log which could be a sign of logging evasion.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
17 days ago
004
The following analytic detects modifications to the registry that disable the Event Tracing for Windows (ETW) feature. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the registry path "*\\SOFTWARE\\Microsoft\\.NETFramework\\ETWEnabled" with a value set to "0x00000000". This activity is significant because disabling ETW can allow attackers to evade detection mechanisms, making it harder for security tools to monitor malicious activities. If confirmed malicious, this could enable attackers to execute payloads with minimal alerts, impairing defenses and potentially leading to further compromise of the system.
Splunk Security@SplunkSecurity
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Splunk Security Content
17 days ago
002
The following analytic detects modifications to the Windows registry aimed at disabling the Registry Editor (regedit). It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the registry path "*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\DisableRegistryTools" with a value of "0x00000001". This activity is significant because malware, such as RATs or trojans, often disable registry tools to prevent the removal of their entries, aiding in persistence and defense evasion. If confirmed malicious, this could hinder incident response efforts and allow the attacker to maintain control over the compromised system.
Splunk Security@SplunkSecurity
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Splunk Security Content
17 days ago
002
The following analytic detects the use of `dism.exe` to remove Windows Defender. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions that include specific parameters for disabling and removing Windows Defender. This activity is significant because adversaries may disable Defender to evade detection and carry out further malicious actions undetected. If confirmed malicious, this could lead to the attacker gaining persistent access, executing additional payloads, or exfiltrating sensitive data without being intercepted by Windows Defender.
Splunk Security@SplunkSecurity
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Splunk Security Content
17 days ago
002
Detects when an SAP audit message ID appears in security audit logs but is absent from the defined monitoring configuration table, which could indicate attempts to bypass or disable monitoring controls.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
12 days ago
000
Detects usage of powershell cmdlets to disable or remove ETW trace sessions
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
17 days ago
002
The following analytic detects attempts to stop security-related services on an endpoint, which may indicate malicious activity. It leverages data from Endpoint Detection and Response (EDR) agents, specifically searching for processes involving the "sc.exe" or "net.exe" command with the "stop" parameter or the PowerShell "Stop-Service" cmdlet. This activity is significant because disabling security services can undermine the organization's security posture, potentially leading to unauthorized access, data exfiltration, or further attacks like malware installation or privilege escalation. If confirmed malicious, this behavior could compromise the endpoint and the entire network, necessitating immediate investigation and response.
Splunk Security@SplunkSecurity
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Splunk Security Content
17 days ago
001
The following analytic identifies modifications in the registry to disable Windows Defender's real-time behavior monitoring. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to registry paths associated with Windows Defender settings. This activity is significant because disabling real-time protection is a common tactic used by malware such as RATs, bots, or Trojans to evade detection. If confirmed malicious, this action could allow an attacker to execute code, escalate privileges, or persist in the environment without being detected by antivirus software.
Splunk Security@SplunkSecurity
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Splunk Security Content
17 days ago
001
The following analytic detects the modification of the Windows Registry key "DisableAntiSpyware" being set to disable. This detection leverages data from the Endpoint.Registry datamodel, specifically looking for the registry value name "DisableAntiSpyware" with a value of "0x00000001". This activity is significant as it is commonly associated with Ryuk ransomware infections, indicating potential malicious intent to disable Windows Defender. If confirmed malicious, this action could allow attackers to disable critical security defenses, facilitating further malicious activities such as data encryption, exfiltration, or additional system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
17 days ago
001
The following analytic detects a registry modification that disables the ETW for the .NET Framework.
It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the COMPlus_ETWEnabled registry value under the "Environment" registry key path for both user (HKCU\Environment) and machine (HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment) scopes.
This activity is significant because disabling ETW can allow attackers to evade Endpoint Detection and Response (EDR) tools and hide their execution from audit logs.
If confirmed malicious, this action could enable attackers to operate undetected, potentially leading to further compromise and persistent access within the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
17 days ago
001
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