Detections

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

1,907 detections

Detects the clearing of Windows event logs using command line tools like wevtutil or PowerShell. This is a standard example rule.
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Ryker Martin@Ryker
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Detections.ai Community
5 months ago
1112
Detects PowerShell scripts attempting to overwrite the amsiContext buffer using Runtime.InteropServices.Marshal.WriteInt32 to disable AMSI scanning. This technique was notably observed in the InstallFix campaign delivering RedLine Stealer.
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Tim Peck@timpeck
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Detections.ai Community
6 months ago
1801,142
Detects the usage of 'wevtutil.exe' to clear critical Windows event logs (Application, Security, System, Windows PowerShell). This activity is often associated with defense evasion tactics used by adversaries, including ransomware like VECT, to remove forensic evidence.
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nomit vyas@xoxo
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Detections.ai Community
6 months ago
120953
Detects PowerShell commands reading their own batch file contents via the %~f0 self-reference combined with .NET ReadAllText, the technique Deep#Door uses to extract its embedded Python payload from install_obf.bat without external network retrieval. The combination of these specific patterns has near-zero legitimate use.
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Tim Peck@timpeck
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SecOps Signals
6 months ago
20198
Powershell use PassThru option to start in background
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
5 months ago
000
Detects PowerShell processes executing commands that include common download cradle patterns (nop, w hidden, bypass) and attempt to retrieve content over HTTP/HTTPS. This often indicates an attempt to download and execute malicious scripts or payloads from a remote source.
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nomit vyas@xoxo
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Detections.ai Community
6 months ago
4077
Adversaries may install a root certificate on a compromised system to avoid warnings when connecting to adversary controlled web servers.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
005
Detects usage of WinAPI functions in PowerShell scripts.
It may indicate attempts to perform actions such as process injection, token stealing, or other malicious activities that leverage Windows API calls.
These techniques are commonly used to evade traditional file-based detections by loading and executing code directly in memory.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
004
Detects tampering of AMSI (Anti-Malware Scan Interface) related registry values via command line tools such as reg.exe or PowerShell.
AMSI provides a generic interface for applications and services to integrate with antimalware products.
Adversaries may disable AMSI to evade detection of malicious scripts and code execution.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
004
Detects attempts to remove Windows Defender configurations using the 'MpPreference' cmdlet
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
004
Detects the use of PowerShell with Uninstall-WindowsFeature or Remove-WindowsFeature cmdlets to disable or remove the Windows Defender GUI feature, a common technique used by adversaries to evade defenses.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
004
Detects code fragments found in small and obfuscated AMSI bypass PowerShell scripts
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
003
Adversaries may abuse container files such as disk image (.iso, .vhd) file formats to deliver malicious payloads that may not be tagged with MOTW.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
003
Detects PowerShell scripts set ACL to of a file or a folder
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
103
Detects PowerShell scripts to set the ACL to a file in the Windows folder
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
003
Detects attempts to remove Windows Defender configuration using the 'MpPreference' cmdlet
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
003
Detects the use of reg.exe or PowerShell to delete the Windows Defender context menu handler registry keys.
This action removes the "Scan with Microsoft Defender" option from the right-click menu for files, directories, and drives.
Attackers may use this technique to hinder manual, on-demand scans and reduce the visibility of the security product.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
003
Detects base64 encoded "MpPreference" PowerShell cmdlet code that tries to modifies or tamper with Windows Defender AV
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
003
Detects calls to "LoadAssemblyFromPath" or "LoadAssemblyFromNS" that are part of the "CL_LoadAssembly.ps1" script. This can be abused to load different assemblies and bypass App locker controls.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
003
Detects the execution of obfuscated PowerShell commands that attempt to install MSI packages via the Windows Installer COM object (`WindowsInstaller.Installer`).
The technique involves manipulating strings to hide functionality, such as constructing class names using string insertion (e.g., 'indowsInstaller.Installer'.Insert(0,'W')) and correcting
malformed URLs (e.g., converting 'htps://' to 'https://') at runtime. This behavior is commonly associated with malware loaders or droppers that aim to bypass static detection
by hiding intent in runtime-generated strings and using legitimate tools for code execution. The use of `InstallProduct` and COM object creation, particularly combined with
hidden window execution and suppressed UI, indicates an attempt to install software (likely malicious) without user interaction.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
003
Detects specific techniques often seen used inside of PowerShell scripts to obfscuate Alias creation
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
002
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