Detections

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

268 detections

Detects the addition of exclusion paths to Microsoft Defender via PowerShell (Add-MpPreference or Set-MpPreference) initiated by non-Microsoft signed processes or specific messaging applications. This behavior is often indicative of malware attempting to exclude malicious payloads from security scanning.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
107
This rule detects a suspicious sequence of events where a process related to Electron (a framework often used for cross-platform desktop applications) executes a hidden, obfuscated PowerShell command, followed by a subsequent PowerShell command to modify Microsoft Defender settings by adding an exclusion path for the 'AppData' directory within 10 minutes of the first process.
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Arnold Chan@slaz
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Hunters
1 month ago
002
Detects malicious processes associated with the HVNC backdoor (e.g., UpdateAssistant.exe, SysMaintenance.exe) concurrently running alongside identified security product processes on the same device. This behavior suggests the malware is performing automated reconnaissance of installed security software to inform further compromise actions.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
002
Detects unexpected crashes or restarts of the Windows Defender service (MsMpEng.exe) occurring in temporal proximity to activities associated with the ShieldCrash PoC or tampering within the Windows Defender object manager namespace. This rule aims to identify potential exploitation attempts targeting Windows Defender, specifically correlating security service instability with known malicious indicators.
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Arnold Chan@slaz
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Hunters
2 months ago
7028
This rule detects multiple distinct methods of modifying, impairing, or disabling Microsoft Defender Antivirus exclusions and tamper protection settings. It identifies suspicious activity through PowerShell commands (Add-MpPreference, Set-MpPreference, Invoke-CimMethod, TamperProtection modification), direct registry modification of Defender exclusion paths, and the use of scheduled tasks to maintain or enforce these changes. The rule flags endpoints where two or more of these distinct techniques are observed in a 24-hour period.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
103
Detects when a single process terminates two or more critical security, database, or backup related processes within a short window. This behavior is often associated with adversary attempts to disable security controls or disrupt database operations, commonly observed during the impact phase of an attack or preparatory to data destruction/encryption.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
005
Detects attempts to disable or modify Windows Defender security features, such as Real-time Monitoring, Tamper Protection, or adding unauthorized exclusion paths via PowerShell cmdlets or direct registry modifications.
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Arnold Chan@slaz
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Detection & Hunting Community
1 month ago
103
Detects attempts to disable or modify Windows Defender security features, such as Real-time Monitoring, Tamper Protection, or adding unauthorized exclusion paths via PowerShell cmdlets or direct registry modifications.
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Arnold Chan@slaz
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Midnight Slayer
1 month ago
103
This rule detects a suspicious sequence of events where a process related to Electron (a framework often used for cross-platform desktop applications) executes a hidden, obfuscated PowerShell command, followed by a subsequent PowerShell command to modify Microsoft Defender settings by adding an exclusion path for the 'AppData' directory within 10 minutes of the first process.
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Arnold Chan@slaz
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Midnight Slayer
1 month ago
001
Detects attempts to bypass or tamper with the Antimalware Scan Interface (AMSI) via direct memory modification or through script command-line arguments. The rule monitors DeviceEvents for AMSI-specific events (e.g., buffer patching, provider tampering) and looks for common PowerShell and scripting engine command-line patterns indicative of AMSI bypass techniques.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
002
Detects attempts to modify Microsoft Defender settings, such as adding file path exclusions via PowerShell, Registry manipulation, or Scheduled Tasks, as well as disabling Tamper Protection. These actions are commonly used by attackers to evade security monitoring by hiding malicious files or disabling protective features.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
002
Detects Microsoft Defender (MsMpEng) performing scan or remediation actions against non-standard filesystem paths, specifically NT object-manager namespace paths or CLFS-driver-prefixed paths. This behavior is indicative of an exploitation attempt (e.g., CVE-2026-69414) where an attacker uses symbolic links and CLFS driver namespaces to redirect the Defender scanning engine to arbitrary files on the system, potentially allowing file reads as SYSTEM.
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Georgios Maragos@Gmarak
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Detections.ai Community
2 months ago
6137
This rule detects potential attempts to tamper with or bypass Windows Defender by monitoring for files or processes named 'ShieldCrash' occurring in close temporal proximity to the creation or modification of files within Windows Defender's shadow or scan directories (BaseNamedObjects\Restricted\WD_SHADOW_ or WD_SCAN). This behavior is often associated with malware attempting to evade security detection.
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Arnold Chan@slaz
Defender - KQL
2 months ago
21042
Detects attempts to disable or modify Windows Defender security features, such as Real-time Monitoring, Tamper Protection, or adding unauthorized exclusion paths via PowerShell cmdlets or direct registry modifications.
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Arnold Chan@slaz
Defender - KQL
1 month ago
002
Detects attempts to disable or modify Windows Defender security features, such as Real-time Monitoring, Tamper Protection, or adding unauthorized exclusion paths via PowerShell cmdlets or direct registry modifications.
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Arnold Chan@slaz
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Hunters
1 month ago
002
Detects when a high volume of distinct security-related processes or services are terminated on a single host within a 2-minute window. This behavior is strongly indicative of an adversary attempting to disable endpoint protection software as part of a post-compromise defensive evasion effort.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
002
Detects the use of PowerShell to modify Windows Defender exclusions by adding the 'C:\' drive root as an exclusion path. This technique, which can be executed via 'Add-MpPreference', 'Set-MpPreference', or 'Invoke-CimMethod', effectively disables real-time scanning across the entire system drive and is often employed by adversaries to hide malicious activity from antivirus detection.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
001
This rule detects potential attempts to tamper with or bypass Windows Defender by monitoring for files or processes named 'ShieldCrash' occurring in close temporal proximity to the creation or modification of files within Windows Defender's shadow or scan directories (BaseNamedObjects\Restricted\WD_SHADOW_ or WD_SCAN). This behavior is often associated with malware attempting to evade security detection.
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Arnold Chan@slaz
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Hunters
2 months ago
5010
This rule detects attempts to tamper with the Anti-Malware Scan Interface (AMSI) or suspicious modifications to the memory of common scripting and proxy processes (powershell.exe, pwsh.exe, rundll32.exe, mshta.exe, wscript.exe, cscript.exe). Such activities are often indicative of an adversary attempting to bypass security detection mechanisms to execute malicious code or hide their presence.
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Arnold Chan@slaz
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Midnight Slayer
1 month ago
001
This rule detects attempts to tamper with the Anti-Malware Scan Interface (AMSI) or suspicious modifications to the memory of common scripting and proxy processes (powershell.exe, pwsh.exe, rundll32.exe, mshta.exe, wscript.exe, cscript.exe). Such activities are often indicative of an adversary attempting to bypass security detection mechanisms to execute malicious code or hide their presence.
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Arnold Chan@slaz
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Detections.ai Community
1 month ago
001
Detects command-line activity associated with Monkey ransomware, specifically attempts to bypass AMSI (patching AmsiScanBuffer, targeting AmsiUtils), disable ETW (Event Tracing for Windows) monitoring, and add Microsoft Defender exclusions to evade detection prior to encryption.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
001
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