EXPLORE DETECTIONS
Windows Powershell Commands from DNS TXT
The following analytic detects execution of powershell commands retrieved from a remote DNS TXT query response. The use of the DNS TXT record for C2 is an uncommon method for malware that is resilient due to the need for DNS in normal networking activities. This can ensure that their C2 is not blocked by any firewalls.
Windows Powershell Cryptography Namespace
The following analytic detects suspicious PowerShell script execution involving the cryptography namespace via EventCode 4104. It leverages PowerShell Script Block Logging to identify scripts using cryptographic functions, excluding common hashes like SHA and MD5. This activity is significant as it is often associated with malware that decrypts or decodes additional malicious payloads. If confirmed malicious, this could allow an attacker to execute further code, escalate privileges, or establish persistence within the environment. Analysts should investigate the parent process, decrypted data, network connections, and the user executing the script.
Windows PowerShell Disable HTTP Logging
The following analytic detects the use of `get-WebConfigurationProperty` and `Set-ItemProperty` commands in PowerShell to disable HTTP logging on Windows systems. This detection leverages PowerShell Script Block Logging, specifically looking for script blocks that reference HTTP logging properties and attempt to set them to "false" or "dontLog". Disabling HTTP logging is significant as it can be used by adversaries to cover their tracks and delete logs, hindering forensic investigations. If confirmed malicious, this activity could allow attackers to evade detection and persist in the environment undetected.
Windows PowerShell Export Certificate
The following analytic detects the use of the PowerShell Cmdlet `export-certificate` by leveraging Script Block Logging. This activity is significant as it may indicate an adversary attempting to exfiltrate certificates from the local Certificate Store on a Windows endpoint. Monitoring this behavior is crucial because stolen certificates can be used to impersonate users, decrypt sensitive data, or facilitate further attacks. If confirmed malicious, this activity could lead to unauthorized access to encrypted communications and sensitive information, posing a severe security risk.
Windows PowerShell Export PfxCertificate
The following analytic detects the use of the PowerShell cmdlet `export-pfxcertificate` by leveraging Script Block Logging. This activity is significant as it may indicate an adversary attempting to exfiltrate certificates from the Windows Certificate Store. Monitoring this behavior is crucial for identifying potential certificate theft, which can lead to unauthorized access and impersonation attacks. If confirmed malicious, this activity could allow attackers to compromise secure communications, authenticate as legitimate users, and escalate their privileges within the network.
Windows PowerShell FakeCAPTCHA Clipboard Execution
This detection identifies potential FakeCAPTCHA/ClickFix clipboard hijacking campaigns by looking for PowerShell execution with hidden window parameters and distinctive strings related to fake CAPTCHA verification. These campaigns use social engineering to trick users into pasting malicious PowerShell commands from their clipboard, typically delivering information stealers or remote access trojans.
Windows PowerShell Get CIMInstance Remote Computer
The following analytic detects the use of the Get-CimInstance cmdlet with the -ComputerName parameter, indicating an attempt to retrieve information from a remote computer. It leverages PowerShell Script Block Logging to identify this specific command execution. This activity is significant as it may indicate unauthorized remote access or information gathering by an attacker. If confirmed malicious, this could allow the attacker to collect sensitive data from remote systems, potentially leading to further exploitation or lateral movement within the network.
Windows Powershell History File Deletion
The following analytic detects the usage of PowerShell to delete its command history file, which may indicate an attempt to evade detection by removing evidence of executed commands. PowerShell stores command history in ConsoleHost_history.txt under the user’s profile directory. Adversaries or malicious scripts may delete this file using Remove-Item, del, or similar commands. This detection focuses on file deletion events targeting the history file, correlating them with recent PowerShell activity. While legitimate users may occasionally clear history, frequent or automated deletions should be investigated for potential defense evasion or post-exploitation cleanup activities.
Windows PowerShell IIS Components WebGlobalModule Usage
The following analytic detects the usage of PowerShell Cmdlets - New-WebGlobalModule, Enable-WebGlobalModule, and Set-WebGlobalModule, which are used to create, enable, or modify IIS Modules. This detection leverages PowerShell Script Block Logging, specifically monitoring EventCode 4104 for these cmdlets. This activity is significant as adversaries may use these lesser-known cmdlets to manipulate IIS configurations, similar to AppCmd.exe, potentially bypassing traditional defenses. If confirmed malicious, this could allow attackers to persist in the environment, manipulate web server behavior, or escalate privileges.
Windows Powershell Import Applocker Policy
The following analytic detects the import of Windows PowerShell Applocker cmdlets, specifically identifying the use of "Import-Module Applocker" and "Set-AppLockerPolicy" with an XML policy. It leverages PowerShell Script Block Logging (EventCode 4104) to capture and analyze script block text. This activity is significant as it may indicate an attempt to enforce restrictive Applocker policies, potentially used by malware like Azorult to disable antivirus products. If confirmed malicious, this could allow an attacker to bypass security controls, leading to further system compromise and persistence.
Windows PowerShell Invoke-RestMethod IP Information Collection
The following analytic detects the use of PowerShell's Invoke-RestMethod cmdlet to collect geolocation data from ipinfo.io or IP address information from api.ipify.org. This behavior leverages PowerShell Script Block Logging to identify scripts that gather external IP information and potential geolocation data. This activity is significant as it may indicate reconnaissance efforts, where threat actors are attempting to determine the geographical location or network details of a compromised system. While some legitimate software may use these services, this pattern is commonly observed in malware and post-exploitation toolkits like those used by Water Gamayun threat actors.
Windows PowerShell Invoke-Sqlcmd Execution
This detection identifies potentially suspicious usage of Invoke-Sqlcmd PowerShell cmdlet, which can be used for database operations and potential data exfiltration. The detection looks for suspicious parameter combinations and query patterns that may indicate unauthorized database access, data theft, or malicious database operations. Threat actors may prefer using PowerShell Invoke-Sqlcmd over sqlcmd.exe as it provides a more flexible programmatic interface and can better evade detection.
Windows Powershell Logoff User via Quser
The following analytic detects the process of logging off a user through the use of the quser and logoff commands. By monitoring for these commands, the analytic identifies actions where a user session is forcibly terminated, which could be part of an administrative task or a potentially unauthorized access attempt. This detection helps identify potential misuse or malicious activity where a user's access is revoked without proper authorization, providing insight into potential security incidents involving account management or session manipulation.
Windows PowerShell Module File Created
Detects the creation of a DLL within the various PowerShell module directories. This can indicate a new module being installed, attempts at ScriptBlock smuggling, or other malicious PowerShell activity utilizing modules. False positives could include installation of legitimate modules.
Windows PowerShell MSIX Package Installation
The following analytic detects the execution of PowerShell commands to install unsigned AppX packages using Add-AppxPackage or Add-AppPackage cmdlets with the -AllowUnsigned flag. This detection leverages PowerShell Script Block Logging (EventCode=4104) to capture the full command content. This activity is significant as adversaries may use unsigned AppX packages to install malicious applications, bypass security controls, or establish persistence. If confirmed malicious, this could allow attackers to install unauthorized applications that may contain malware, backdoors, or other malicious components.
Windows PowerShell Process Implementing Manual Base64 Decoder
The following analytic identifies Windows PowerShell processes that implement a manual Base64 decoder. Threat actors often use Base64 encoding to obfuscate malicious payloads or commands within PowerShell scripts. By manually decoding Base64 strings, attackers can evade detection mechanisms that look for standard decoding functions like using the "-enc" flag or the "FromBase64String" function. This detection focuses on PowerShell processes that exhibit characteristics of manual Base64 decoding, such as the presence of specific string manipulation methods and bitwise operations. Security teams should investigate any instances of such activity, especially if found in conjunction with other suspicious behaviors or on systems that should not be using PowerShell for such tasks.
Windows PowerShell Process With Malicious String
The following analytic detects the execution of multiple offensive toolkits and commands through the process execution datamodel. This method captures commands given directly to powershell.exe, allowing for the identification of suspicious activities including several well-known tools used for credential theft, lateral movement, and persistence. If confirmed malicious, this could lead to unauthorized access, privilege escalation, and potential compromise of sensitive information within the environment.
Windows Powershell RemoteSigned File
The following analytic identifies the use of the "remotesigned" execution policy for PowerShell scripts. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions containing "remotesigned" and "-File". This activity is significant because the "remotesigned" policy allows locally created scripts to run without restrictions, posing a potential security risk. If confirmed malicious, an attacker could execute unauthorized scripts, leading to code execution, privilege escalation, or persistence within the environment.
Windows PowerShell ScheduleTask
The following analytic detects potential malicious activities involving PowerShell's task scheduling cmdlets. It leverages PowerShell Script Block Logging (EventCode 4104) to identify unusual or suspicious use of cmdlets like 'New-ScheduledTask' and 'Set-ScheduledTask'. This activity is significant as attackers often use these cmdlets for persistence and remote execution of malicious code. If confirmed malicious, this could allow attackers to maintain access, deliver additional payloads, or execute ransomware, leading to data theft or other severe impacts. Immediate investigation and mitigation are crucial to prevent further compromise.
Windows PowerShell Script Block With Malicious String
The following analytic detects the execution of multiple offensive toolkits and commands by leveraging PowerShell Script Block Logging (EventCode=4104). This method captures and logs the full command sent to PowerShell, allowing for the identification of suspicious activities including several well-known tools used for credential theft, lateral movement, and persistence. If confirmed malicious, this could lead to unauthorized access, privilege escalation, and potential compromise of sensitive information within the environment.
Windows PowerShell Script From WindowsApps Directory
The following analytic identifies the execution of PowerShell scripts from the WindowsApps directory, which is a common technique used in malicious MSIX package execution. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process command lines and parent process paths. This activity is significant as adversaries have been observed using MSIX packages with embedded PowerShell scripts (particularly StartingScriptWrapper.ps1) to execute malicious code. If confirmed malicious, this could allow attackers to execute arbitrary code, establish persistence, or deliver malware while evading traditional detection mechanisms.
Windows PowerShell Script TabExpansion Direct Call
Detects specific indicators associated with the execution of the TabExpansion internal function in PowerShell. Calling this function directly is not normal and can be indicative of malicious activity such as TabShell. Due to the way PowerShell internals work it can be used in conjunction with directory transversal to load any PowerShell functions even in a sandboxed session. False positives could include legitimate usage of the TabExpansion function but calling it directly is very rare.
Windows PowerShell WMI Win32 ScheduledJob
The following analytic detects the use of the Win32_ScheduledJob WMI class via PowerShell script block logging. This class, which manages scheduled tasks, is disabled by default due to security concerns and must be explicitly enabled through registry modifications. The detection leverages PowerShell event code 4104 and script block text analysis. Monitoring this activity is crucial as it may indicate malicious intent, especially if the class was enabled by an attacker. If confirmed malicious, this could allow attackers to persist in the environment by creating scheduled tasks.
Windows PowerSploit GPP Discovery
The following analytic detects the execution of the Get-GPPPassword PowerShell cmdlet, which is used to search for unsecured credentials in Group Policy Preferences (GPP). This detection leverages PowerShell Script Block Logging to identify specific script block text associated with this cmdlet. Monitoring this activity is crucial as it can indicate an attempt to retrieve and decrypt stored credentials from SYSVOL, potentially leading to unauthorized access. If confirmed malicious, this activity could allow an attacker to escalate privileges or move laterally within the network by exploiting exposed credentials.