Detections

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

1,793 detections

The following analytic detects processes with names consisting of a single letter, which is often indicative of malware or an attacker attempting to evade detection. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant because attackers use such techniques to obscure their presence and carry out malicious activities like data theft or ransomware attacks. If confirmed malicious, this behavior could lead to unauthorized access, data exfiltration, or system compromise. Immediate investigation is required to determine the legitimacy of the process.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0177
This analytic identifies when a malicious file is detected within the Microsoft Office 365 ecosystem by the Advanced Threat Protection (ATP) engine. Attackers often stage and execute malicious files from within cloud environments like Office 365. Monitoring detections from built-in Office 365 capabilities, such as those enhanced by Safe Attachments and Safe Links, is crucial for identifying and responding to threats.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0042
This detection identifies instances where Windows Explorer.exe spawns PowerShell or cmd.exe processes with abnormally large padding (50 or more spaces) in the command line. This specific pattern is a key indicator of the ZDI-CAN-25373 Windows shortcut zero-day vulnerability exploitation, where threat actors craft malicious LNK files containing padded content to trigger code execution. The excessive spacing in the command line is used to manipulate the way Windows processes the shortcut file, enabling arbitrary code execution. This technique has been actively exploited by multiple APT groups in targeted attacks, with malicious LNK files being delivered through both HTTP and SMB protocols. The presence of significant command line padding when Explorer.exe launches command shells is highly suspicious and warrants immediate investigation.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0040
The following analytic identifies when a malicious file is detected within the SharePoint Online ecosystem. Attackers may stage and execute malicious files from within the Microsoft Office 365 ecosystem. Any detections from built-in Office 365 capabilities should be monitored and responded to appropriately. Certain premium Office 365 capabilities further enhance these detection and response functions.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0037
This detection identifies instances where Windows Explorer.exe spawns PowerShell or cmd.exe processes, particularly focusing on executions initiated by LNK files. This behavior is associated with the ZDI-CAN-25373 Windows shortcut zero-day vulnerability, where specially crafted LNK files are used to trigger malicious code execution through cmd.exe or powershell.exe. This technique has been actively exploited by multiple APT groups in targeted attacks through both HTTP and SMB delivery methods.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2037
The analytic detects the creation of a file named "license.dat" in the %appdata% or %programdata% directories. This behavior is strongly associated with the IcedID malware, which uses this file to inject its core bot into other processes for banking credential theft. The detection leverages Sysmon EventCode 11 to monitor file creation events in these directories. This activity is significant as it indicates a potential malware infection aiming to steal sensitive banking information. If confirmed malicious, the attacker could gain unauthorized access to financial data, leading to significant financial loss and data breaches.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0032
This analytic detects executables running from public or temporary locations that are communicating over Windows domain authentication ports/protocols such as LDAP (389), LDAPS (636), and Kerberos (88). It leverages network traffic data to identify processes originating from user-controlled directories. This activity is significant because legitimate applications rarely run from these locations and attempt domain authentication, making it a potential indicator of compromise. If confirmed malicious, attackers could leverage this to access domain resources, potentially leading to further exploitation and lateral movement within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0031
Detects exploitation of LNK file command-line length discrepancy, where attackers hide malicious commands beyond the 260-character UI limit while the actual command-line argument field supports 4096 characters using whitespace padding (e.g., 0x20, 0x09-0x0D). Adversaries insert non-printable whitespace characters (e.g., Line Feed \x0A, Carriage Return \x0D) to pad the visible section of the LNK file, pushing malicious commands past the UI-visible boundary. The hidden payload, executed at runtime but invisible in Windows Explorer properties, enables stealthy execution and evasion—commonly used for social engineering attacks. This rule flags suspicious use of such padding observed in real-world attacks.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0013
Detects exploitation of LNK file command-line length discrepancy, where attackers hide malicious commands beyond the 260-character UI limit while the actual command-line argument field supports 4096 characters using whitespace padding (e.g., 0x20, 0x09-0x0D).
Adversaries insert non-printable whitespace characters (e.g., Line Feed \x0A, Carriage Return \x0D) to pad the visible section of the LNK file, pushing malicious commands past the UI-visible boundary.
The hidden payload, executed at runtime but invisible in Windows Explorer properties, enables stealthy execution and evasion—commonly used for social engineering attacks.
This rule flags suspicious use of such padding observed in real-world attacks.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
000
Yara rule that detects WolfsBane backdoor.
ReversingLabs Yara@ReversingLabsYara
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ReversingLabs Yara
2 years ago
001
Detects HTTP requests to low reputation Top-Level Domains (TLDs) or for files with suspicious extensions, which may indicate an attempt to download malicious content or establish command and control.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0024
This rule identifies when a user downloads, views, or copies a potentially malicious file from Google Drive. The detection is triggered if the file has a public visibility setting ('people_with_link' or 'public_on_the_web') and its name matches a common executable or script file extension (e.g., .dll, .exe, .scr, .jar, .pif, .app, .dmg, .pkg, .elf, .so, .bin, .deb, .rpm, .sh, .hta, .lnk). This aims to detect user interaction with suspicious files that could lead to execution of malicious code.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
30327
This rule detects when a user bypasses Chrome Safe Browsing warnings for potentially dangerous content or downloads. It specifically looks for events where Chrome Management reports a bad navigation event, dangerous download event, content transfer event, or unscanned file event, and the security result indicates the event was 'BYPASSED' by the user. The rule also assigns a risk score based on the category of the bypassed threat, with higher scores for malware, dangerous hosts, and social engineering.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
1072
This rule detects when Amazon GuardDuty identifies a malicious or suspicious file being executed on an Amazon EC2 instance or a container workload. It specifically looks for GuardDuty findings with product event types 'MaliciousFile' or 'SuspiciousFile', excluding any sample findings.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
0034
Detects creation and movement of .lnk files to specific folders
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
002
Amazon GuardDuty detects a malicious or suspicious file on an Amazon EC2 instance or a container workload.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
001
Identifies when a user downloads a potentially malicious file from Google Drive.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
000
Detects exploits that leverage CVE-2017-11882 by monitoring for the execution of EQNEDT32.EXE as a parent process, which is indicative of the vulnerability being exploited to launch further malicious processes like mshta.exe.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0045
Detects the creation of a file by WinRAR with a double extension and a space in the filename, specifically targeting the temporary directory. This pattern is indicative of an exploitation attempt related to CVE-2023-38331, a vulnerability in WinRAR that allows for arbitrary code execution through specially crafted archives.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
3033
This rule detects the execution of 'csc.exe' as a sub-process of 'WINWORD.EXE'. This specific process relationship is indicative of exploitation attempts leveraging CVE-2017-8759, where a crafted document (opened by Winword) can lead to the execution of arbitrary code, often using csc.exe (C# compiler) to compile and execute malicious code on the fly.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
2032
Detects the download of potentially malicious file types (executables, scripts, documents, archives, etc.) from domains using suspicious or commonly abused Top-Level Domains (TLDs). This rule aims to identify initial access attempts often associated with phishing or drive-by download campaigns.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1030
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