Detections

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

4,528 detections

The following analytic detects the suspicious creation of msmpeng.exe or mpsvc.dll in non-default Windows Defender folders. It leverages the Endpoint.Filesystem datamodel to identify instances where these files are created outside their expected directories. This activity is significant because it is associated with the REvil ransomware, which uses DLL side-loading to execute malicious payloads. If confirmed malicious, this could lead to ransomware deployment, resulting in data encryption, system compromise, and potential data loss or extortion.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0031
The analytic detects a process writing the `dynwrapx.dll` file to disk and registering it in the registry. This activity is significant because DynamicWrapperX is an ActiveX component often used in scripts to call Windows API functions, and its presence in non-standard locations is highly suspicious. If confirmed malicious, this could allow an attacker to execute arbitrary code, escalate privileges, or maintain persistence within the environment. Immediate investigation of parallel processes and registry modifications is recommended.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0031
The analytic detects the creation of shim database files (.sdb) in default directories using the sdbinst.exe application. It leverages filesystem activity data to identify file writes to the Windows\AppPatch\Custom directory. This activity is significant because shims can intercept and alter API calls, potentially allowing attackers to bypass security controls or execute malicious code. If confirmed malicious, this could lead to unauthorized code execution, privilege escalation, or persistent access within the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0031
The analytic detects the creation of the 'comadmin.dat' file in the '%windows%\system32\Com' directory. This file is associated with Snake Malware's installation process, which involves dropping a kernel driver and a custom DLL. The presence of this file indicates potential compromise, leading to privilege escalation and persistent access through a malicious kernel driver.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0031
The following analytic identifies the creation of suspicious .aspx files in specific directories associated with Exchange exploitation by the HAFNIUM group and the ProxyShell vulnerability. It detects this activity by monitoring the MSExchangeMailboxReplication.exe process, which typically does not write .aspx files. This behavior is significant as it may indicate an active exploitation attempt on Exchange servers. If confirmed malicious, attackers could gain unauthorized access, execute arbitrary code, or maintain persistence within the environment. Immediate investigation and remediation are crucial to prevent further compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0030
The analytic detects the creation of the `doas.conf` file on a Linux host. This file is used by the `doas` utility to allow standard users to perform tasks as root, similar to `sudo`. The detection leverages filesystem data, focusing on the creation of the `doas.conf` file. This activity is significant because it can indicate an attempt to gain elevated privileges, potentially by an adversary. If confirmed malicious, this could allow an attacker to execute commands with root privileges, leading to full system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0029
The following analytic detects the creation of a file named "test.txt" within the Windows system directory, indicative of Samsam ransomware propagation. It leverages file-system activity data from the Endpoint data model, specifically monitoring file paths within the Windows System32 directory. This activity is significant as it aligns with known Samsam ransomware behavior, which uses such files for propagation and execution. If confirmed malicious, this could lead to ransomware deployment, resulting in data encryption, system disruption, and potential data loss. Immediate investigation and remediation are crucial to prevent further damage.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0029
The following analytic detects when a process other than explorer.exe writes to the Windows Recycle Bin. It leverages the Endpoint.Filesystem and Endpoint.Processes data models in Splunk to identify any process writing to the "*$Recycle.Bin*" file path, excluding explorer.exe. This activity is significant because it may indicate an attacker attempting to hide their actions, potentially leading to data theft, ransomware, or other malicious outcomes. If confirmed malicious, this behavior could allow an attacker to persist in the environment and evade detection by security tools.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1029
The analytic identifies the creation of a .crmlog file within the %windows%\Registration directory, typically with a format of <RANDOM_GUID>.<RANDOM_GUID>.crmlog. This activity is significant as it is associated with the Snake malware, which uses this file for its operations. If confirmed malicious, this could indicate the presence of Snake malware, leading to potential data exfiltration, system compromise, and further malicious activities. Immediate investigation is required to mitigate the threat.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0029
This analytic detects a sharp increase in the number of files written to a specific host. It leverages the Endpoint.Filesystem data model, focusing on 'created' actions and comparing current file write counts against historical averages and standard deviations. This activity is significant as a sudden spike in file writes can indicate malicious activities such as ransomware encryption or data exfiltration. If confirmed malicious, this behavior could lead to significant data loss, system compromise, or further propagation of malware within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0028
This analytic detects instances where the `rundll32.exe` process creates new executable (`.exe`) or dynamic link library (`.dll`) files. This behavior is identified by monitoring Sysmon EventCode 11 (FileCreate). `rundll32.exe` is a legitimate Windows utility, but it is frequently abused by adversaries to execute malicious code, establish persistence, or escalate privileges. Malware families like IcedID are known to leverage `rundll32.exe` to drop payloads in common user-writable directories such as `Temp`, `AppData`, or `ProgramData`. Detecting this activity can indicate the presence of malicious software attempting to deploy its components.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0027
The analytic detects the `wermgr.exe` process creating an executable file. This behavior is unusual because `wermgr.exe` is typically associated with error reporting, not file creation. Such activity is significant as it may indicate TrickBot malware, which injects code into `wermgr.exe` to execute malicious actions like downloading additional payloads. If confirmed malicious, this could lead to further malware infections, data exfiltration, or system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0026
Detects the dropping and potential execution of DarkGate loader components, specifically AutoIt scripts (.au3) or compiled AutoIt executables (autoit3.exe), within the C:\temp directory. This activity is indicative of DarkGate malware infection attempts, often leveraging vulnerabilities like CVE-2024-21412.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0036
Detects the creation of files with scripting or executable extensions by the MySQL daemon process. This activity could indicate the abuse of MySQL User Defined Functions (UDFs) to download and execute malware, often as part of a broader compromise or to establish persistence.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
2023
This rule detects the creation or modification of anonymous links in OneDrive. Anonymous links can be used to export files from OneDrive, posing a risk of data leakage, especially in organizations that do not support their creation.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
0041
This rule detects the wmRAT backdoor by identifying specific byte patterns associated with its core functionalities. These functionalities include connecting to a command and control (C2) server, finding and exfiltrating files, receiving data and writing it to files, and gathering system information. The rule looks for a combination of these distinct byte patterns to minimize false positives.
ReversingLabs Yara@ReversingLabsYara
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ReversingLabs Yara
2 years ago
0031
Detects suspicious file creations within the Palo Alto Networks PAN-OS' parent telemetry folder, specifically looking for filenames containing patterns indicative of OS command injection attempts related to CVE-2024-3400. These files are processed by the 'dt_curl' script, which can lead to arbitrary command execution if device telemetry is enabled and filenames are crafted to bypass shell-subprocess restrictions.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1064
Detects the creation of Python path configuration files (.pth) within Python library folders on Windows systems. These files can be maliciously used for code execution and persistence, as modules referenced by them are executed at every Python startup (v3.5+), regardless of whether they are imported by the calling script. The rule specifically targets files ending with '.pth' in paths matching '\(venv|python(.+)?)\lib\site-packages\', while filtering out known legitimate .pth files like 'pywin32.pth' and 'distutils-precedence.pth'.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
2059
Detects the creation of Python path configuration files (.pth) within Python library folders on macOS. These files can be maliciously used for code execution and persistence, as modules referenced by them are executed at every Python startup (v3.5+), regardless of whether they are explicitly imported by a script. The rule specifically looks for files ending with '.pth' in the '/lib/python3.([5-9]|[0-9]{2})/site-packages/' directory structure.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1052
Detects the creation of Python path configuration files (.pth) within Python library folders on Linux systems. These files can be maliciously used for code execution and persistence, as modules referenced by them are executed at every Python startup (v3.5+), regardless of whether they are imported by the calling script. The rule specifically looks for files ending with '.pth' in typical Python site-packages directories.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
2044
Detects the creation of JavaScript files within the Windows DriverStore directory. This activity has been observed in attacks by the Forest Blizzard APT (also known as Star Blizzard) to exploit CVE-2022-38028 in the Windows Print Spooler service. The adversary modified a JavaScript constraints file and executed it with SYSTEM-level permissions to achieve privilege escalation and credential access.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0019
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