Detections

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

11,829 detections

The following analytic detects attempts to change the default file association for files without an extension to open with Notepad.exe. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on specific command-line patterns and registry modifications. This activity is significant as it can indicate an attempt to manipulate file handling behavior, a technique observed in APT and ransomware attacks like Prestige. If confirmed malicious, this could allow attackers to execute arbitrary code by tricking users into opening files, potentially leading to system compromise or data exfiltration.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0046
Detects M365 Copilot impersonation and roleplay jailbreak attempts where users try to manipulate the AI into adopting alternate personas, behaving as unrestricted entities, or impersonating malicious AI systems to bypass safety controls. The detection searches exported eDiscovery prompt logs for roleplay keywords like "pretend you are," "act as," "you are now," "amoral," and "roleplay as" in the Subject_Title field. Prompts are categorized into specific impersonation types (AI_Impersonation, Malicious_AI_Persona, Unrestricted_AI_Persona, etc.) to identify attempts to override the AI's safety guardrails through persona injection attacks.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1044
The following analytic identifies the creation or deletion of scheduled tasks using the schtasks.exe utility with the -create or -delete flags. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant as it can indicate unauthorized system manipulation or malicious intent, often associated with threat actors like Dragonfly and incidents such as the SUNBURST attack. If confirmed malicious, this activity could allow attackers to execute code, escalate privileges, or persist within the environment, posing a significant security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0042
The following analytic identifies the execution of RAR utilities to archive files on a system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, GUIDs, and command-line arguments. This activity is significant as threat actors, including red-teamers and malware like DarkGate, use RAR archiving to compress and exfiltrate collected data from compromised hosts. If confirmed malicious, this behavior could lead to the unauthorized transfer of sensitive information to command and control servers, posing a severe risk to data confidentiality and integrity.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1042
The analytic detects the use of Windows Curl.exe to download a file to a suspicious location, such as AppData, ProgramData, or Public directories. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions that include the -O or --output options. This activity is significant because downloading files to these locations can indicate an attempt to bypass security controls or establish persistence. If confirmed malicious, this behavior could lead to unauthorized code execution, data exfiltration, or further compromise of the system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
This rule detects the usage of the 'ssh.exe' binary as a proxy to launch other programs. This technique can be abused by adversaries for defense evasion and to execute arbitrary commands. The detection specifically looks for 'ssh.exe' being spawned by 'sshd.exe' or for 'ssh.exe' command lines containing 'ProxyCommand=' or 'PermitLocalCommand=yes' and 'LocalCommand'.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
3118
The analytic detects the execution of rundll32.exe loading syssetup.dll via the LaunchINFSection function. 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 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.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0043
This analytic detects the execution of the Windows built-in tool Fsutil.exe with the "behavior", "set" and "SymlinkEvaluation" parameters. Attackers can abuse this to alter symlink evaluation behavior on Windows, potentially enabling remote traversal over SMB shares or evading defenses. Such changes should be uncommon or even rare in enterprise environments and should be investigated.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2043
The following analytic detects the execution of "rundll32.exe" with inline protocol handlers such as "JavaScript", "VBScript", and "About". This behavior is identified using Endpoint Detection and Response (EDR) telemetry, focusing on command-line arguments. This activity is significant as it is often associated with fileless malware or application whitelisting bypass techniques. If confirmed malicious, this could allow an attacker to execute arbitrary code, bypass security controls, and maintain persistence within the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0040
The following analytic detects the execution of the 'rmdir' command with '/s' and '/q' options to delete files and directory trees. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions and process metadata. This activity is significant as it may indicate malware attempting to remove traces or components during cleanup operations. If confirmed malicious, this behavior could allow attackers to eliminate forensic evidence, hinder incident response efforts, and maintain persistence by removing indicators of compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
The analytic detects the execution of rundll32.exe loading advpack.dll or ieadvpack.dll via the LaunchINFSection function. This method is identified using 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 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 script content, network connections, and any spawned child processes for further context.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
This analytic detects attempts to add a certificate to the untrusted certificate store using the 'certutil -addstore' command. This activity is significant as it may indicate an attacker trying to disable security tools to gain unauthorized access. If confirmed malicious, this could lead to the compromise of system security, allowing attackers to bypass defenses and potentially escalate privileges or persist in the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1041
The analytic detects the creation of scheduled tasks in Windows using `schtasks.exe` with the `/xml` or `-xml` parameter. This activity is significant as it is a common technique for establishing persistence or achieving privilege escalation, often used by malware like Trickbot and Winter-Vivern. While creating a scheduled task via XML may be legitimate, it can also be abused by attackers. If confirmed malicious, this could allow attackers to maintain access, execute additional payloads, and potentially lead to data theft or ransomware deployment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
The following analytic detects the execution of hh.exe (HTML Help) loading a Compiled HTML Help (CHM) file from a remote URL. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions containing URLs. This activity is significant as it can indicate an attempt to execute malicious scripts via CHM files, potentially leading to unauthorized code execution. If confirmed malicious, this could allow an attacker to run scripts using engines like JScript or VBScript, leading to further system compromise or data exfiltration.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0038
The following analytic detects the use of certutil.exe to add a certificate to the Root certificate store using the "-addstore" flag. In this case, the certificate is loaded from a temporary file path (e.g., %TEMP%) or other uncommon locations (e.g. C:\Users\Public\), which is highly suspicious and uncommon in legitimate administrative activity. This behavior may indicate an adversary is installing a malicious root certificate to intercept HTTPS traffic, impersonate trusted entities, or bypass security controls. The use of flags such as -f (force) and -Enterprise, combined with loading .tmp files from user-writable locations, is consistent with post-exploitation activity seen in credential theft and adversary-in-the-middle (AiTM) attacks. This should be investigated immediately, especially if correlated with unauthorized privilege use or prior certificate modifications. You should monitor when new certificates are added to the root store because this store is what your system uses to decide which websites, apps, and software can be trusted. If an attacker manages to add their own certificate there, they can silently intercept encrypted traffic, impersonate trusted websites, or make malicious programs look safe. This means they could steal sensitive data, bypass security tools, and keep access to your system even after other malware is removed.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0040
The following analytic identifies instances where mshta.exe has been renamed and executed. It leverages Endpoint Detection and Response (EDR) data, specifically focusing on the original file name field to detect discrepancies. This activity is significant because renaming mshta.exe is a common tactic used by attackers to evade detection and execute malicious scripts. If confirmed malicious, this could allow an attacker to execute arbitrary code, potentially leading to system compromise, data exfiltration, or further lateral movement within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0037
The following analytic detects the execution of rundll32.exe loading setupapi.dll and iesetupapi.dll via the LaunchINFSection function. This behavior is identified using Endpoint Detection and Response (EDR) telemetry, focusing on process creation events and command-line arguments. This activity is significant as it indicates a potential application control bypass, allowing an attacker to execute arbitrary script code. If confirmed malicious, this technique could enable code execution, privilege escalation, or persistence within the environment, posing a severe threat to system integrity and security.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
The following analytic detects attempts to change the command value of a file association of an extension to open with Notepad.exe. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on specific command-line patterns and registry modifications. This activity is significant as it can indicate an attempt to manipulate file handling behavior, a technique observed in APT and ransomware attacks like Prestige. After changing the extension of all encrypted files to a new one, Prestige ransomware modifies the file association for that extension to open with Notepad.exe in order to display a ransom note.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
The analytic detects Microsoft OneNote spawning `mshta.exe`, a behavior often associated with spearphishing attacks. This activity is significant as it is commonly used by malware families like TA551, AsyncRat, Redline, and DCRAT to execute malicious scripts. If confirmed malicious, this could allow attackers to execute arbitrary code, potentially leading to data exfiltration, system compromise, or further malware deployment. Immediate investigation and containment are recommended.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0036
Detects a sequence of commands associated with the anti-analysis techniques of the Stealit malware. Stealit executes specific wmic and tasklist commands in quick succession from a single parent process to check for debuggers, analysis tools, and virtual environments.
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Tim Peck@timpeck
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Detections.ai Community
1 year ago
00108
The following analytic detects the execution of hh.exe (HTML Help) using InfoTech Storage Handlers to load Windows script code from a Compiled HTML Help (CHM) file. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant because it can be used to execute malicious scripts embedded within CHM files, potentially leading to code execution. If confirmed malicious, this technique could allow an attacker to execute arbitrary code, escalate privileges, or persist within the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1035
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