EXPLORE DETECTIONS
Windows Administrative Shares Accessed On Multiple Hosts
The following analytic detects a source computer accessing Windows administrative shares (C$, Admin$, IPC$) on 30 or more remote endpoints within a 5-minute window. It leverages Event IDs 5140 and 5145 from file share events. This behavior is significant as it may indicate an adversary enumerating network shares to locate sensitive files, a common tactic used by threat actors. If confirmed malicious, this activity could lead to unauthorized access to critical data, lateral movement, and potential compromise of multiple systems within the network.
Windows Admon Default Group Policy Object Modified
The following analytic detects modifications to the default Group Policy Objects (GPOs) in an Active Directory environment. It leverages Splunk's Admon to monitor updates to the "Default Domain Policy" and "Default Domain Controllers Policy." This activity is significant because changes to these default GPOs can indicate an adversary with privileged access attempting to gain further control, establish persistence, or deploy malware across multiple hosts. If confirmed malicious, such modifications could lead to widespread policy enforcement changes, unauthorized access, and potential compromise of the entire domain environment.
Windows Admon Group Policy Object Created
The following analytic detects the creation of a new Group Policy Object (GPO) using Splunk's Admon data. It identifies events where a new GPO is created, excluding default "New Group Policy Object" entries. Monitoring GPO creation is crucial as adversaries can exploit GPOs to escalate privileges or deploy malware across an Active Directory network. If confirmed malicious, this activity could allow attackers to control system configurations, deploy ransomware, or propagate malware, significantly compromising the network's security.
Windows Advanced Installer MSIX with AI_STUBS Execution
The following analytic identifies the execution of Advanced Installer MSIX Package Support Framework (PSF) components, specifically the AI_STUBS executables with the original filename 'popupwrapper.exe'. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process paths and original filenames. This activity is significant as adversaries have been observed packaging malicious content within MSIX files built with Advanced Installer to bypass security controls. These AI_STUBS executables (with original filename 'popupwrapper.exe') are hallmark artifacts of potentially malicious MSIX packages. If confirmed malicious, this could allow attackers to execute arbitrary code, establish persistence, or deliver malware while evading traditional detection mechanisms.
Windows AI Platform DNS Query
The following analytic detects DNS queries initiated by the Windows AI Platform to domains associated with Hugging Face, OpenAI, and other popular providers of machine learning models and services. Monitoring these DNS requests is important because it can reveal when systems are accessing external AI platforms, which may indicate the use of third-party AI resources or the transfer of sensitive data outside the organization’s environment. Detecting such activity enables organizations to enforce data governance policies, prevent unapproved use of external AI services, and maintain visibility into potential data exfiltration risks. Proactive monitoring provides better control over AI model usage and helps safeguard organizational data flows.
Windows Alternate Data Stream Created Over Local Share
The following analytic detects the creation of an NTFS alternate data stream (ADS) accessed over a local administrative share targeting the loopback address (127.0.0.1). It leverages Windows Security Event Logs with EventCode 5145 to identify this activity. Legitimate local processes access files directly rather than through a local SMB share. This behavior is a hallmark of the ShieldBreak exploit, which abuses a symbolic link swap through a loopback share to redirect a privileged, Defender-driven write into an alternate data stream on a system-owned file, ultimately landing attacker content in C:\Windows\System32. If confirmed malicious, this activity indicates an in-progress local privilege escalation attempt and should be investigated immediately.
Windows Alternate DataStream - Base64 Content
The following analytic detects the creation of Alternate Data Streams (ADS) with Base64 content on Windows systems. It leverages Sysmon EventID 15, which captures file creation events, including the content of named streams. ADS can conceal malicious payloads, making them significant for SOC monitoring. This detection identifies hidden streams that may contain executables, scripts, or configuration data, often used by malware to evade detection. If confirmed malicious, this activity could allow attackers to hide and execute payloads, persist in the environment, or access sensitive information without being easily detected.
Windows Alternate DataStream - Executable Content
The following analytic detects the writing of data with an IMPHASH value to an Alternate Data Stream (ADS) in the NTFS file system. It leverages Sysmon Event ID 15 and regex to identify files with a Portable Executable (PE) structure. This activity is significant as it may indicate a threat actor staging malicious code in hidden areas for persistence or future execution. If confirmed malicious, this could allow attackers to execute hidden code, maintain persistence, or escalate privileges within the environment.
Windows Alternate DataStream - Process Execution
The following analytic detects when a process attempts to execute a file from within an NTFS file system alternate data stream. This detection leverages process execution data from sources like Windows process monitoring or Sysmon Event ID 1, focusing on specific processes known for such behavior. This activity is significant because alternate data streams can be used by threat actors to hide malicious code, making it difficult to detect. If confirmed malicious, this could allow an attacker to execute hidden code, potentially leading to unauthorized actions and further compromise of the system.
Windows Anomalous Registry Value Length in Environment Key
The following analytic detects creation or modification of registry values under a user or system Environment key (paths matching *\Environment\*) where the stored value exceeds 2,000 characters. Legitimate environment variables are typically short strings (paths, tokens, or flags); unusually long values can indicate adversaries or malware staging encoded payloads, bloated malicious PATH entries, or other data in a location that is loaded for every interactive session. This behavior has been observed in contexts such as .NET infostealer activity. Analysts should validate the writing process, value content, and whether the change aligns with trusted software deployment or administrative tasks.
Windows Anonymous Pipe Activity
The following analytic detects the creation or connection of anonymous pipes for inter-process communication (IPC) within a Windows environment. Anonymous pipes are commonly used by legitimate system processes, services, and applications to transfer data between related processes. However, adversaries frequently abuse anonymous pipes to facilitate stealthy process injection, command-and-control (C2) communication, credential theft, or privilege escalation. This detection monitors for unusual anonymous pipe activity, particularly involving non-system processes, unsigned executables, or unexpected parent-child process relationships. While legitimate use cases exist—such as Windows services, software installers, or security tools—unusual or high-frequency anonymous pipe activity should be investigated for potential malware, persistence mechanisms, or lateral movement techniques.
Windows Apache Benchmark Binary
The following analytic detects the execution of the Apache Benchmark binary (ab.exe), commonly used by MetaSploit payloads. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process creation events where the original file name is ab.exe. This activity is significant as it may indicate the presence of a MetaSploit attack, which uses Apache Benchmark to generate malicious payloads. If confirmed malicious, this could lead to unauthorized network connections, further system compromise, and potential data exfiltration. Immediate investigation is required to determine the intent and scope of the activity.
Windows App Layer Protocol Qakbot NamedPipe
The following analytic detects a suspicious process creating or connecting to a potential Qakbot named pipe. It leverages Sysmon EventCodes 17 and 18, focusing on specific processes known to be abused by Qakbot and identifying randomly generated named pipes in GUID form. This activity is significant as Qakbot malware uses named pipes for inter-process communication after code injection, facilitating data theft. If confirmed malicious, this behavior could indicate a Qakbot infection, leading to unauthorized data access and potential exfiltration from the compromised host.
Windows App Layer Protocol Wermgr Connect To NamedPipe
The following analytic detects the wermgr.exe process creating or connecting to a named pipe. It leverages Sysmon EventCodes 17 and 18 to identify these actions. This activity is significant because wermgr.exe, a legitimate Windows OS Problem Reporting application, is often abused by malware such as Trickbot and Qakbot to execute malicious code. If confirmed malicious, this behavior could indicate that an attacker has injected code into wermgr.exe, potentially allowing them to communicate covertly, escalate privileges, or persist within the environment.
Windows AppCertDLL Modification Via Command Line
This analytic detects attempts to modify AppCertDLL registry keys via some command line utility. Values under this key are used to specify DLLs loaded by the Windows Session Manager. Such modifications can be abused by attackers to load malicious code early in the system startup process, enabling persistent malware execution with high privileges. If confirmed malicious, this behavior may lead to system compromise, persistence, and the evasion of security controls.
Windows AppCertDLL Modification Via Registry
This analytic detects attempts to modify AppCertDLL registry entries. Values under this registry entry are used to specify DLLs loaded by the Windows Session Manager. Such modifications can be abused by attackers to load malicious code early in the system startup process, enabling persistent malware execution with high privileges. If confirmed malicious, this behavior may lead to system compromise, persistence, and the evasion of security controls.
Windows Application Layer Protocol RMS Radmin Tool Namedpipe
The following analytic detects the use of default or publicly known named pipes associated with the RMX remote admin tool. It leverages Sysmon EventCodes 17 and 18 to identify named pipe creation and connection events. This activity is significant as the RMX tool has been abused by adversaries and malware like Azorult to collect data from targeted hosts. If confirmed malicious, this could indicate unauthorized remote administration capabilities, leading to data exfiltration or further compromise of the affected system. Immediate investigation is required to determine the legitimacy of this tool's presence.
Windows Application Whitelisting Bypass Attempt via Rundll32
The following analytic detects the execution of rundll32.exe calling one of the following DLLs: - Advpack.dll - Ieadvpack.dll - Syssetup.dll - Setupapi.dll with one of the following functions: "LaunchINFSection", "InstallHinfSection", "SetupInfObjectInstallAction". This method is identified through Endpoint Detection and Response (EDR) telemetry, focusing on command-line executions and process details. This activity is significant as it indicates a potential application control or whitelisting bypass, allowing script code execution from a file. If confirmed malicious, an attacker could execute arbitrary code, potentially leading to privilege escalation, persistence, or further network compromise. Investigate the script content, network connections, and any spawned child processes for further context.
Windows AppLocker Block Events
The following analytic detects attempts to bypass application restrictions by identifying Windows AppLocker policy violations. It leverages Windows AppLocker event logs, specifically EventCodes 8007, 8004, 8022, 8025, 8029, and 8040, to pinpoint blocked actions. This activity is significant for a SOC as it highlights potential unauthorized application executions, which could indicate malicious intent or policy circumvention. If confirmed malicious, this activity could allow an attacker to execute unauthorized applications, potentially leading to further system compromise or data exfiltration.
Windows AppLocker Execution from Uncommon Locations
The following analytic identifies the execution of applications or scripts from uncommon or suspicious file paths, potentially indicating malware or unauthorized activity. It leverages Windows AppLocker event logs and uses statistical analysis to detect anomalies. By calculating the average and standard deviation of execution counts per file path, it flags paths with execution counts significantly higher than expected. This behavior is significant as it can uncover malicious activities or policy violations. If confirmed malicious, this activity could allow attackers to execute unauthorized code, leading to potential system compromise or data breaches.
Windows AppLocker Privilege Escalation via Unauthorized Bypass
The following analytic utilizes Windows AppLocker event logs to identify attempts to bypass application restrictions. AppLocker is a feature that allows administrators to specify which applications are permitted to run on a system. This analytic is designed to identify attempts to bypass these restrictions, which could be indicative of an attacker attempting to escalate privileges. The analytic uses EventCodes 8007, 8004, 8022, 8025, 8029, and 8040 to identify these attempts. The analytic will identify the host, full file path, and target user associated with the bypass attempt. These EventCodes are related to block events and focus on 5 attempts or more.
Windows AppLocker Rare Application Launch Detection
The following analytic detects the launch of rarely used applications within the environment, which may indicate the use of potentially malicious software or tools by attackers. It leverages Windows AppLocker event logs, aggregating application launch counts over time and flagging those that significantly deviate from the norm. This behavior is significant as it helps identify unusual application activity that could signal a security threat. If confirmed malicious, this activity could allow attackers to execute unauthorized code, potentially leading to further compromise of the system.
Windows AppX Deployment Full Trust Package Installation
The following analytic detects the installation of MSIX/AppX packages with full trust privileges. This detection leverages Windows event logs from the AppXDeployment-Server, specifically focusing on EventCode 400 which indicates a package deployment operation. Full trust packages are significant as they run with elevated privileges outside the normal AppX container restrictions, allowing them to access system resources that regular AppX packages cannot. Adversaries have been observed leveraging full trust MSIX packages to deliver malware, as documented in recent threat intelligence reports. If confirmed malicious, these packages could allow attackers to execute arbitrary code with elevated privileges, establish persistence, or deliver malware while evading traditional detection mechanisms.
Windows AppX Deployment Package Installation Success
This analytic detects successful MSIX/AppX package installations on Windows systems by monitoring EventID 854 in the Microsoft-Windows-AppXDeployment-Server/Operational log. This event is generated when an MSIX/AppX package has been successfully installed on a system. While most package installations are legitimate, monitoring these events can help identify unauthorized or suspicious package installations, especially when correlated with other events such as unsigned package installations (EventID 603 with Flags=8388608) or full trust package installations (EventID 400 with HasFullTrust=true).