Detections

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

3,120 detections

Detects execution of the "esxcli" command with the "vm" and "kill" flag in order to kill/shutdown a specific VM.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
001
This analytic detects the execution of the 'fsutil' command with the 'setzerodata' parameter, which zeros out a target file. This activity is significant because it is a technique used by ransomware, such as LockBit, to evade detection by erasing its malware path after encrypting the host. If confirmed malicious, this action could hinder forensic investigations and allow attackers to cover their tracks, complicating incident response efforts.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0042
The following analytic detects the execution of the Windows command line to log off a host machine. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on processes involving `shutdown.exe` with specific parameters. This activity is significant as it is often associated with Advanced Persistent Threats (APTs) and Remote Access Trojans (RATs) like dcrat, which use this technique to disrupt operations, aid in system destruction, or inhibit recovery. If confirmed malicious, this could lead to system downtime, data loss, or hindered incident response efforts.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0036
The following analytic identifies attempts to delete AWS Bedrock Knowledge Bases, which are resources that store and manage domain-specific information for AI models. It monitors AWS CloudTrail logs for DeleteKnowledgeBase API calls. This activity could indicate an adversary attempting to remove knowledge bases after compromising credentials, potentially to disrupt business operations or remove traces of data access. Deleting knowledge bases could impact model performance, remove critical business context, or be part of a larger attack to degrade AI capabilities. If confirmed malicious, this could represent a deliberate attempt to cause service disruption or data loss.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2078
The following analytic detects the modification of registry keys related to the desktop wallpaper settings. It leverages Sysmon EventCode 13 to identify changes to the "Control Panel\\Desktop\\Wallpaper" and "Control Panel\\Desktop\\WallpaperStyle" registry keys, especially when the modifying process is not explorer.exe or involves suspicious file paths like temp or public directories. This activity is significant as it can indicate ransomware behavior, such as the REVIL ransomware, which changes the wallpaper to display a ransom note. If confirmed malicious, this could signify a compromised machine and the presence of ransomware, leading to potential data encryption and extortion.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1078
The analytic detects the creation of shadow copies using `vssadmin.exe` or `wmic.exe`. This activity is significant because creating shadow copies can be a precursor to ransomware attacks or data exfiltration, allowing attackers to bypass file locks and access sensitive data. If confirmed malicious, this behavior could enable attackers to maintain persistence, recover deleted files, or prepare for further malicious activities, posing a significant risk to the integrity and confidentiality of the system. Adversaries may create shadow copies to access the NTDS.dit file for credential dumping or to exfiltrate data.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1063
This analytic identifies an abnormally high number of cloud instances being destroyed within a 4-hour period. It leverages cloud infrastructure logs and applies a probability density model to detect outliers. This activity is significant for a SOC because a sudden spike in destroyed instances could indicate malicious activity, such as an insider threat or a compromised account attempting to disrupt services. If confirmed malicious, this could lead to significant operational disruptions, data loss, and potential financial impact due to the destruction of critical cloud resources.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1062
This detection identifies when an administrator manually triggers device management configuration policy sync events, on-demand remediation scripts, or remotely restarts devices within Microsoft Intune. While this functionality can be used legitimately to expedite policy delivery, it can also be abused by an attacker to quickly deploy malicious payloads or disrupt systems.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1062
This analytic identifies when an O365 email account sends an email and then hard deletes email 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 activity. Threat actors often use this technique to prevent defenders and victims from knowing the account has been compromised.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0062
The analytic detects the use of `sc.exe` to delete a Windows service. It leverages Endpoint Detection and Response (EDR) data, focusing on process execution logs that capture command-line arguments. This activity is significant because adversaries often delete services to disable security mechanisms or critical system functions, aiding in evasion and persistence. If confirmed malicious, this action could lead to the termination of essential security services, allowing attackers to operate undetected and potentially escalate their privileges or maintain long-term access to the compromised system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0062
This analytic detects the creation of AWS KMS keys with an encryption policy accessible to everyone, including external entities. It leverages AWS CloudTrail logs from Amazon Security Lake 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
2060
The analytic identifies users with KMS keys performing encryption operations on S3 buckets. It leverages AWS CloudTrail logs to detect the `CopyObject` event where server-side encryption with AWS KMS is specified. This activity is significant as it may indicate unauthorized or suspicious encryption of data, potentially masking exfiltration or tampering efforts. If confirmed malicious, an attacker could be encrypting sensitive data to evade detection or preparing it for exfiltration, posing a significant risk to data integrity and confidentiality.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1058
The analytic detects the deletion of shadow copies using the vssadmin.exe or wmic.exe utilities. This activity is significant because deleting shadow copies is a common tactic used by attackers to prevent recovery and hide their tracks. If confirmed malicious, this action could hinder incident response efforts and allow attackers to maintain persistence and cover their activities, making it crucial for security teams to investigate promptly.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1055
The following analytic identifies when an O365 email account hard deletes an excessive number of emails within a short period (within 1 hour). This behavior may indicate a compromised account where the threat actor is attempting to permanently purge a large amount of items from the mailbox. Threat actors may attempt to remove evidence of their activity by purging items from the compromised mailbox. Some account owner legitimate behaviors can trigger this alert, however these actions may not be aligned with organizational expectations / best practice behaviors.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0053
The analytic detects when a user deletes a repository in GitHub Enterprise. The detection monitors GitHub Enterprise audit logs for repository deletion events, which could indicate unauthorized removal of critical source code and project resources. For a SOC, identifying repository deletions is crucial as it may signal account compromise, insider threats, or malicious attempts to destroy intellectual property and disrupt development operations. The impact could be severe, potentially resulting in permanent loss of source code, documentation, project history, and other critical assets if proper backups are not maintained. Repository deletion could halt development workflows, cause significant business disruption, and require substantial effort to restore from backups if available. Additionally, unauthorized repository removal could be part of a larger attack campaign aimed at destroying or compromising enterprise assets.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0052
The following analytic identifies when an O365 email recipient receives and then deletes emails related to password or banking/payroll changes within a short period. This behavior may indicate a compromised account where the threat actor is attempting to redirect the victims payroll to an attacker controlled bank account.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0051
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
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Splunk Security Content
1 year ago
2150
The analytic identifies a spike in API activity related to the deletion of S3 buckets in an AWS environment. It uses AWS CloudTrail logs to detect anomalies by comparing current deletion activity against a historical baseline. Unusual spikes in S3 bucket deletions could indicate malicious actions such as data exfiltration or unauthorized data destruction, leading to significant data loss, disruption of services, and potential exposure of sensitive information. Immediate investigation is required to determine the legitimacy of the activity.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0049
The analytic detects the execution of the "swapoff" command with the "-a" argument, which disables the swapping of all paging devices on a Linux system. This activity is significant because disabling swap can be a tactic used by malware, such as Awfulshred, to evade detection and hinder forensic analysis. If confirmed malicious, this action could allow an attacker to manipulate system memory management, potentially leading to data corruption, system instability, or evasion of memory-based detection mechanisms.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0048
This analytic detects previously unseen processes within the Kubernetes environment on master or worker nodes. It leverages process metrics collected via an OTEL collector and hostmetrics receiver, with data pulled from Splunk Observability Cloud. The detection compares processes observed in the last hour against those seen in the previous 30 days. Identifying new processes is crucial as they may indicate unauthorized activity or attempts to compromise the node. If confirmed malicious, these processes could lead to data exfiltration, privilege escalation, denial-of-service attacks, or the introduction of malware, posing significant risks to the Kubernetes cluster.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0047
This analytic identifies a large volume of DNS ANY queries, which may indicate a DNS amplification attack. It leverages the Network_Resolution data model to count DNS queries of type "ANY" directed to specific destinations. This activity is significant because DNS amplification attacks can overwhelm network resources, leading to Denial of Service (DoS) conditions. If confirmed malicious, this activity could disrupt services, degrade network performance, and potentially be part of a larger Distributed Denial of Service (DDoS) attack, impacting the availability of critical infrastructure.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1047
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