Detections

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

3,120 detections

The following analytic identifies the creation of open/public S3 buckets in AWS. It detects this activity by analyzing AWS CloudTrail events for `PutBucketAcl` actions where the access control list (ACL) grants permissions to all users or authenticated users. This activity is significant because open S3 buckets can expose sensitive data to unauthorized access, leading to data breaches. If confirmed malicious, an attacker could read, write, or fully control the contents of the bucket, potentially leading to data exfiltration or tampering.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1045
This analytic detects the use of PowerShell to delete shadow copies, a common tactic used by ransomware to prevent data recovery. It specifically looks for PowerShell Script Block Logging (EventCode 4104) events containing keywords like "ShadowCopy" along with "Delete" or "Remove" in the ScriptBlockText. Successful execution of such commands can lead to irreversible data loss and hinder recovery efforts.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2045
The following analytic detects the modification of registry keys to disable System Restore on a machine. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to registry paths associated with System Restore settings. This activity is significant because disabling System Restore can hinder recovery efforts and is a tactic often used by Remote Access Trojans (RATs) to maintain persistence on an infected system. If confirmed malicious, this action could prevent system recovery, allowing the attacker to sustain their foothold and potentially cause further damage or data loss.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0045
The analytic detects ARP Poisoning attacks by monitoring for Dynamic ARP Inspection (DAI) errors on Cisco network devices. It leverages logs from Cisco devices, specifically looking for events where the ARP inspection feature has disabled an interface due to suspicious activity. This activity is significant because ARP Poisoning can allow attackers to intercept, modify, or disrupt network traffic, leading to potential data breaches or denial of service. If confirmed malicious, this could enable attackers to perform man-in-the-middle attacks, compromising the integrity and confidentiality of network communications.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1045
The following analytic detects suspicious modifications to cron jobs on Linux systems using the crontab command with list parameters. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant as it may indicate an attempt to establish persistence or execute malicious code on a schedule. If confirmed malicious, the impact could include unauthorized code execution, data destruction, or other damaging outcomes. Further investigation should analyze the added cron job, its associated command, and any related processes.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0044
The analytic detects attempts to stop or clear a service on Linux systems. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on processes like "systemctl," "service," and "svcadm" executing stop commands. This activity is significant as adversaries often terminate security or critical services to disable defenses or disrupt operations, as seen in malware like Industroyer2. If confirmed malicious, this could lead to the disabling of security mechanisms, allowing attackers to persist, escalate privileges, or deploy destructive payloads, severely impacting system integrity and availability.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0044
This analytic is developed to detect the usage of BitLocker commands used to disable or impact boot settings. The malware ShrinkLocker uses various commands to change how BitLocker handles encryption, potentially bypassing TPM requirements, enabling BitLocker without TPM, and enforcing specific startup key and PIN configurations. Such modifications can weaken system security, making it easier for unauthorized access and data breaches. Detecting these changes is crucial for maintaining robust encryption and data protection.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0044
The following analytic identifies instances where four or more distinct detection analytics are associated with malicious command line behavior on a specific host. This detection leverages the Command Line Interface (CLI) data from various sources to identify suspicious activities. This behavior is significant as it often indicates attempts to execute malicious commands, access sensitive data, install backdoors, or perform other nefarious actions. If confirmed malicious, attackers could gain unauthorized control, exfiltrate information, escalate privileges, or launch further attacks within the network, leading to severe compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0044
This detection identifies web requests to domains that match previously decommissioned S3 buckets through web proxy logs. This activity is significant because attackers may attempt to access or 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
2044
The following analytic detects the creation of AWS KMS keys with an encryption policy accessible to everyone, including external entities. It leverages AWS CloudTrail logs to identify `CreateKey` or `PutKeyPolicy` events where the `kms:Encrypt` action is granted to all principals. This activity is significant as it may indicate a compromised account, allowing an attacker to misuse the encryption key to target other organizations. If confirmed malicious, this could lead to unauthorized data encryption, potentially disrupting operations and compromising sensitive information across multiple entities.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1043
The following analytic detects when AWS S3 bucket versioning is suspended by a user. It leverages AWS CloudTrail logs to identify `PutBucketVersioning` events with the `VersioningConfiguration.Status` set to `Suspended`. This activity is significant because disabling versioning can prevent recovery of deleted or modified data, which is a common tactic in ransomware attacks. If confirmed malicious, this action could lead to data loss and hinder recovery efforts, severely impacting data integrity and availability.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
1042
The analytic detects when a user removes an organization from GitHub Enterprise. The detection monitors GitHub Enterprise audit logs for organization deletion events, which could indicate unauthorized removal of critical business resources. For a SOC, identifying organization removals is crucial as it may signal account compromise, insider threats, or malicious attempts to disrupt business operations by deleting entire organizational structures. The impact could be severe, potentially resulting in loss of source code, repositories, team structures, access controls, and other critical organizational assets. This disruption could halt development workflows, cause data loss, and require significant effort to restore from backups if available. Additionally, unauthorized organization removal could be part of a larger attack campaign aimed at destroying or compromising enterprise assets.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0042
The analytic detects the execution of the SysRq hack to reboot a Linux system host. It identifies processes executing the command to pipe 'b' to /proc/sysrq-trigger. This activity is significant as it is an uncommon method to reboot a system and was observed in the Awfulshred malware wiper. If confirmed malicious, this technique could indicate the presence of suspicious processes and potential system compromise, leading to unauthorized reboots and disruption of services.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0042
The following analytic detects `PutBucketLifecycle` events in AWS CloudTrail logs where a user sets a lifecycle rule for an S3 bucket with an expiration period of fewer than three days. This detection leverages CloudTrail logs to identify suspicious lifecycle configurations. This activity is significant because attackers may use it to delete CloudTrail logs quickly, thereby evading detection and impairing forensic investigations. If confirmed malicious, this could allow attackers to cover their tracks, making it difficult to trace their actions and respond to the breach effectively.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
The following analytic identifies when an O365 email account sends and then hard deletes an email to an external recipient within a short period (within 1 hour). This behavior may indicate a compromised account where the threat actor is attempting to remove forensic artifacts or evidence of exfiltration activity. This behavior is often seen when threat actors want to reduce the probability of detection by the compromised account owner.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
The following analytic detects excessive file deletion events in the Windows Defender folder. It leverages Sysmon EventCodes 23 and 26 to identify processes deleting multiple files within this directory. This behavior is significant as it may indicate an attempt to corrupt or disable Windows Defender, a key security component. If confirmed malicious, this activity could allow an attacker to disable endpoint protection, facilitating further malicious actions without detection.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
1041
This analytic detects attempts to stop security-related services on an endpoint, which may indicate malicious activity. It leverages data from Endpoint Detection and Response (EDR) agents, specifically searching for processes involving the "sc.exe" or "net.exe" command with the "stop" parameter or the PowerShell "Stop-Service" cmdlet. This activity is significant because disabling security services can undermine the organization's security posture, potentially leading to unauthorized access, data exfiltration, or further attacks like malware installation or privilege escalation. If confirmed malicious, this behavior could compromise the endpoint and the entire network, necessitating immediate investigation and response.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0041
The analytic detects `PutBucketLifecycle` events in AWS CloudTrail logs where a user sets a lifecycle rule for an S3 bucket with an expiration period of fewer than three days. This activity is significant because attackers may use it to delete CloudTrail logs quickly, thereby evading detection and impairing forensic investigations. If confirmed malicious, this could allow attackers to cover their tracks, making it difficult to trace their actions and respond to the breach effectively.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0039
The analytic detects modifications to the Windows error recovery boot configurations using `bcdedit.exe` with flags such as "recoveryenabled" and "no". This activity is significant because ransomware often disables recovery options to prevent system restoration, making it crucial for SOC analysts to investigate. If confirmed malicious, this could hinder recovery efforts, allowing ransomware to cause extensive damage and complicate remediation.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0039
The following analytic detects the use of the 'dd' command to overwrite files on a Linux system. It leverages data from Linux Auditd telemetry, 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
avatar
Splunk Security Content
1 year ago
0039
The analytic detects the deletion of service files on a Linux machine within system directories (e.g., /etc/systemd/, /lib/systemd/, /run/systemd/). This activity is significant because attackers may delete or modify services to disable security features, evade defenses, impair system functionality, or execute a destructive payload. Immediate investigation is required to determine the responsible process and user.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0039
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