Detections

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

6,695 detections

The following analytic identifies the execution of `nltest.exe` with command-line arguments `/domain_trusts` or `/all_trusts` to query Domain Trust information. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs and command-line arguments. This activity is significant as it indicates potential reconnaissance efforts by adversaries to understand domain trust relationships, which can inform their lateral movement strategies. If confirmed malicious, this activity could enable attackers to map out trusted domains, facilitating further compromise and pivoting within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
The analytic identifies processes with command-line parameters associated with web browser credential dumping tools, specifically targeting behaviors used by Remcos RAT malware. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions and specific file paths. This activity is significant as it indicates potential credential theft, a common tactic in broader cyber-espionage campaigns. If confirmed malicious, attackers could gain unauthorized access to sensitive web credentials, leading to further system compromise and data breaches.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1033
The following analytic detects the execution of rundll32.exe with the DllRegisterServer command to load a DLL. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions and process details. This activity is significant as it may indicate an attempt to register a malicious DLL, which can be a method for code execution or persistence. If confirmed malicious, an attacker could gain unauthorized code execution, escalate privileges, or maintain persistence within the environment, posing a severe security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
The analytic detects the execution of `query.exe` with command-line arguments aimed at discovering logged-in users. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant as adversaries may use `query.exe` to gain situational awareness and perform Active Directory discovery on compromised endpoints. If confirmed malicious, this behavior could allow attackers to identify active users, aiding in further lateral movement and privilege escalation within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
This rule detects the deletion of Access Control List (ACL) entries on the domain root object within Active Directory. Such an action is a significant change with high impact, as it can alter fundamental security permissions for the entire domain. Microsoft guidance suggests that all changes at this level should be reviewed. The rule extracts details about the old and new ACL values, the operation type, the affected object, and the user performing the action. It also attempts to resolve SIDs to user or group names for better context.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
The following analytic identifies the execution of `auditpol.exe` with the "/set", "/option" and "/value:disable" command-line arguments used to disable specific auditing options of the audit policy. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity can be significant as it indicates potential defense evasion by adversaries or Red Teams, aiming to limit data that can be leveraged for detections and audits. If confirmed malicious, this behavior could allow attackers to bypass defenses, and plan further attacks, potentially leading to full machine compromise or lateral movement.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
This analytic detects the use of the `sfc.exe` utility to stop the Immunet Protect service. The `sfc.exe` utility is part of Cisco Secure Endpoint installation. This detection leverages endpoint telemetry, focusing on command-line executions involving the `-k` parameter. This activity is significant as it indicates potential tampering with defensive mechanisms. If confirmed malicious, attackers could partially blind the EDR, enabling further compromise and lateral movement within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
The analytic detects the modification of the InProcServer32 registry key by reg.exe, indicative of potential COM hijacking. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and command-line execution logs. COM hijacking is significant as it allows adversaries to insert malicious code that executes in place of legitimate software, providing a means for persistence. If confirmed malicious, this activity could enable attackers to execute arbitrary code, disrupt legitimate system components, and maintain long-term access to the compromised environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1033
This analytic detects a computer account requesting a Kerberos ticket, which is unusual as typically user accounts request these tickets. This detection leverages Windows Security Event Logs, specifically EventCode 4768, to identify instances where the TargetUserName ends with a dollar sign ($), indicating a computer account. This activity is significant because it may indicate the use of tools like KrbUpRelay or other Kerberos-based attacks. If confirmed malicious, this could allow attackers to impersonate computer accounts, potentially leading to unauthorized access and lateral movement within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1033
The analytic detects the addition of Service Principal Names (SPNs) HOST and RestrictedKrbHost to a computer account, indicative of KrbRelayUp behavior. This detection leverages Windows Security Event Logs, specifically EventCode 4741, to identify changes in SPNs. This activity is significant as it is commonly associated with Kerberos-based attacks, which can be used to escalate privileges or perform lateral movement within a network. If confirmed malicious, this behavior could allow an attacker to impersonate services, potentially leading to unauthorized access to sensitive resources.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
The following analytic detects the execution of the Windows OS tool cmdkey.exe, which is used to create stored usernames, passwords, or credentials. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs and command-line arguments. This activity is significant because cmdkey.exe is often abused by post-exploitation tools and malware, such as Darkgate, to gain unauthorized access. If confirmed malicious, this behavior could allow attackers to escalate privileges and maintain persistence on the targeted host, facilitating further attacks and potential data breaches.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
The analytic identifies the use of protocol handlers executed via the command line. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and command-line telemetry. This activity is significant because protocol handlers can be exploited to execute arbitrary commands or launch applications, potentially leading to unauthorized actions. If confirmed malicious, an attacker could use this technique to gain code execution, escalate privileges, or maintain persistence within the environment, posing a significant security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
This analytic detects an increase in modifications to Active Directory groups or objects. Frequent changes to AD groups or objects can indicate potential security risks, such as unauthorized access attempts, impairing defenses, or establishing persistence. By monitoring AD logs for unusual modification patterns, this detection helps identify suspicious behavior that could compromise the integrity and security of the AD environment. The rule specifically looks for a statistically significant increase in the number of unique objects modified by a source user over a 5-minute span, compared to their historical average and standard deviation.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
The analytic detects the disabling of important audit policies by leveraging EventCode 4719 from Windows Security Event Logs. This event indicates changes where success or failure auditing is removed for specific subcategories. Such activity suggests an attacker may be attempting to evade detection by tampering with audit policies, potentially after gaining access to a system, including a domain controller. If confirmed malicious, this could lead to severe consequences, including data theft, privilege escalation, and full network compromise. Immediate investigation is required to determine the source and intent of the change.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
The analytic detects a high volume of Kerberos service ticket requests (more than 30) from a single source within a 5-minute window, specifically focusing on requests with computer names as the Service Name (Event ID 4769). This behavior may indicate malicious activities such as lateral movement, malware staging, or reconnaissance, potentially leading to unauthorized access and network compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
This analytic identifies suspicious command-line activity where `cmd.exe` is used to fetch environment variables via the `set` command, but the parent process is not a typical shell like `cmd.exe`, `explorer.exe`, or `powershell`. This behavior is often observed in malware, such as Qakbot, to gather system information. Detection of this activity could indicate a compromised parent process, potentially leading to further malicious actions like arbitrary command execution, privilege escalation, or persistence.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
The following analytic identifies instances where three or more distinct registry modification events associated with MITRE ATT&CK Technique T1112 are detected. It leverages data from the Risk data model in Splunk, focusing on registry-related sources and MITRE technique annotations. This activity is significant because multiple registry modifications can indicate an attempt to persist, hide malicious configurations, or erase forensic evidence. If confirmed malicious, this behavior could allow attackers to maintain persistent access, execute malicious code, and evade detection, posing a severe threat to the integrity and security of the affected host.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
The following analytic detects suspicious modifications to the Windows registry keys related to file compression color and information tips. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the "ShowCompColor" and "ShowInfoTip" values under the "Microsoft\\Windows\\CurrentVersion\\Explorer\\Advanced" path. This activity is significant as it was observed in the Hermetic Wiper malware, indicating potential malicious intent to alter file attributes and user interface elements. If confirmed malicious, this could signify an attempt to manipulate file visibility and deceive users, potentially aiding in further malicious activities.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
This analytic identifies a single source user failing to authenticate with more than 30 unique target users using explicit credentials on a host. It leverages Windows Event 4648, which is generated when a process attempts an account logon by explicitly specifying account credentials. This detection is significant as it may indicate a Password Spraying attack, where an adversary attempts to gain initial access or elevate privileges within an Active Directory environment. If confirmed malicious, this activity could lead to unauthorized access, privilege escalation, and potential compromise of sensitive information.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
The following analytic detects suspicious modifications to the EventLog security descriptor registry value for defense evasion. It leverages data from the Endpoint.Registry data model, focusing on changes to the "CustomSD" value within the "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Eventlog\<Channel>\CustomSD" path. This activity is significant as changes to the access permissions of the event log could blind security products and help attackers evade defenses. If confirmed malicious, this could allow attackers to block users and security products from viewing, ingesting and interacting event logs.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
The analytic detects changes in a Windows service's security descriptor where a new deny access control entry (ACE) has been added. It specifically looks for executions of 'sc.exe' with the 'sdset' flag, targeting any service, and including a deny ACE. Such modifications can be used by attackers to escalate privileges, disable security services, or blind defenses by preventing legitimate users or services from interacting with the modified service.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
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