Detections

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

3,120 detections

This analytic detects the use of PowerShell to execute the 'quser' and 'logoff' commands in sequence. This combination indicates an attempt to identify active user sessions and then forcibly terminate one or more of them. This activity could be part of legitimate administrative tasks, but it can also be indicative of unauthorized access attempts, session manipulation, or an adversary attempting to disrupt user access or cover their tracks. Monitoring for this pattern helps identify potential misuse or malicious activity where a user's access is revoked without proper authorization.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0035
The analytic detects the deletion of a service from the Windows Registry under CurrentControlSet\Services. It leverages data from the Endpoint.Registry datamodel, specifically monitoring registry paths and actions related to service deletion. This activity is significant as adversaries may delete services to evade detection and hinder incident response efforts. If confirmed malicious, this action could disrupt legitimate services, impair system functionality, and potentially allow attackers to maintain a lower profile within the environment, complicating detection and remediation efforts.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0035
The following analytic detects the deletion of init daemon scripts on a Linux machine. It leverages filesystem event logs to identify when files within the /etc/init.d/ directory are deleted. This activity is significant because init daemon scripts control the start and stop of critical services, and their deletion can indicate an attempt to impair security features or evade defenses. If confirmed malicious, this behavior could allow an attacker to disrupt essential services, execute destructive payloads, or persist undetected in the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0034
The following analytic detects multiple attempts to stop or delete services on a system using `net.exe` or `sc.exe`. It leverages Endpoint Detection and Response (EDR) telemetry, focusing on process names and command-line executions within a one-minute window. This activity is significant as it may indicate an adversary attempting to disable security or critical services to evade detection and further their objectives. If confirmed malicious, this could lead to the attacker gaining persistence, escalating privileges, or disrupting essential services, thereby compromising the system's security posture.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0034
This analytic detects the creation of files without extensions in critical Windows folders like "System32\drivers" and "syswow64\drivers". This activity is significant as it may indicate the presence of destructive malware, such as HermeticWiper, which drops driver components in these directories. If confirmed malicious, this behavior could lead to severe system compromise, including boot sector wiping, resulting in potential data loss and system inoperability.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1034
This detection identifies DNS queries to domains that match previously decommissioned S3 buckets. This activity is significant because attackers may attempt to recreate deleted S3 buckets that were previously public to hijack them for malicious purposes. If successful, this could allow attackers to host malicious content or exfiltrate data through compromised bucket names that may still be referenced by legitimate applications.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1034
This analytic identifies a process making a DNS query to Discord, excluding legitimate Discord application paths. It leverages Sysmon logs with Event ID 22 to detect DNS queries containing "discord" in the QueryName field. This activity is significant because Discord can be abused by adversaries to host and download malicious files, as seen in the WhisperGate campaign. If confirmed malicious, this could indicate malware attempting to download additional payloads from Discord, potentially leading to further code execution and compromise of the affected system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0034
The following analytic detects the execution of a suspicious `bcdedit` command that configures a host to boot in safe mode with network support. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions involving `bcdedit.exe` with specific parameters. This activity is significant because it is a known technique used by BlackMatter ransomware to force a compromised host into safe mode for continued encryption. If confirmed malicious, this could allow attackers to bypass certain security controls, persist in the environment, and continue their malicious activities.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
The analytic detects attempts to disable a service on a Linux system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on processes like "systemctl," "service," and "svcadm" with commands containing "disable." This activity is significant as adversaries may disable security or critical services to evade detection and facilitate further malicious actions, such as deploying destructive payloads. If confirmed malicious, this could lead to the termination of essential security services, allowing attackers to persist undetected and potentially cause significant damage to the system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1033
The following analytic detects a high frequency of file deletions in the /etc/ folder on Linux systems. It leverages the Endpoint.Filesystem data model to identify instances where 200 or more files are deleted within an hour, grouped by process name and process ID. This behavior is significant as it may indicate the presence of wiper malware, such as AcidRain, which aims to delete critical system files. If confirmed malicious, this activity could lead to severe system instability, data loss, and potential disruption of services.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1033
The following analytic identifies the presence of files containing the keyword "Ryuk" in any folder on the C drive, indicative of Ryuk ransomware activity. It leverages the Endpoint Filesystem data model to detect file paths matching this pattern. This activity is significant as Ryuk ransomware is known for its destructive impact, encrypting critical files and demanding ransom. If confirmed malicious, this could lead to significant data loss, operational disruption, and financial damage due to ransom payments and recovery efforts. Immediate investigation and response are crucial to mitigate potential damage.
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
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
The following analytic detects the stopping of the Windows Security Account Manager (SAM) service via command-line, typically using the "net stop samss" command. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant because stopping the SAM service can disrupt authentication mechanisms and is often associated with ransomware attacks like Ryuk. If confirmed malicious, this action could lead to unauthorized access, privilege escalation, and potential system-wide compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
This analytic detects the use of WMIC to delete volume shadow copies, which is a common technique used by ransomware actors to prevent system recovery. Ransomware like Cactus often delete shadow copies before encrypting files to ensure victims cannot recover their data without paying the ransom. This behavior is particularly concerning as it indicates potential ransomware activity or malicious actors attempting to prevent system recovery.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1033
This analytic identifies failed attempts to delete AWS IAM groups. It leverages AWS CloudTrail logs to detect events where the DeleteGroup action fails due to errors like NoSuchEntityException, DeleteConflictException, or AccessDenied. This activity is significant as it may indicate unauthorized attempts to modify IAM group configurations, which could be a precursor to privilege escalation or other malicious actions. If confirmed malicious, this could allow an attacker to disrupt IAM policies, potentially leading to unauthorized access or denial of service within the AWS environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0032
The following analytic detects the use of the 'dd' command to overwrite files on a Linux system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs that include command-line details. This activity is significant because adversaries often use the 'dd' command to destroy or irreversibly overwrite files, disrupting system availability and services. If confirmed malicious, this behavior could lead to data destruction, making recovery difficult and potentially causing significant operational disruptions.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0032
The following analytic detects the deletion of critical directories on a Linux machine using the `rm` command with argument rf. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions targeting directories like /boot, /var/log, /etc, and /dev. This activity is significant because deleting these directories can severely disrupt system operations and is often associated with destructive campaigns like Industroyer2. If confirmed malicious, this action could lead to system instability, data loss, and potential downtime, making it crucial for immediate investigation and response.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0032
The following analytic detects the use of 'schtasks.exe' to schedule forced system reboots using the 'shutdown' and '/create' flags. It leverages endpoint process data to identify instances where these specific command-line arguments are used. This activity is significant because it may indicate an adversary attempting to disrupt operations or force a reboot to execute further malicious actions. If confirmed malicious, this could lead to system downtime, potential data loss, and provide an attacker with an opportunity to execute additional payloads or evade detection.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0032
The following analytic detects when a Windows service is modified from a start type to disabled. It leverages system event logs, specifically EventCode 7040, to identify this change. This activity is significant because adversaries often disable security or other critical services to evade detection and maintain control over a compromised host. If confirmed malicious, this action could allow attackers to bypass security defenses, leading to further exploitation and persistence within the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0032
This analytic identifies an excessive number of system events where services are modified from a running or enabled state to a disabled state. It leverages Windows Event Logs (EventCode 7040) to detect multiple service state changes on a single host. This activity is significant as it may indicate an adversary attempting to disable security applications or other critical services, potentially leading to defense evasion or destructive actions. If confirmed malicious, this behavior could allow attackers to disable security defenses, disrupt system operations, and achieve their objectives on the compromised system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0032
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