Detections

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

2,588 detections

The analytic detects when an EC2 snapshot is shared publicly by analyzing AWS CloudTrail events. This detection method leverages CloudTrail logs to identify modifications in snapshot permissions, specifically when the snapshot is shared outside the originating AWS account. This activity is significant as it may indicate an attempt to exfiltrate sensitive data stored in the snapshot. If confirmed malicious, an attacker could gain unauthorized access to the snapshot's data, potentially leading to data breaches or further exploitation of the compromised information.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0046
The following analytic detects outbound emails with attachments sent from an internal email domain to an external domain. It leverages Gsuite Gmail logs, parsing the source and destination email domains, and flags emails with fewer than 20 outbound instances. This activity is significant as it may indicate potential data exfiltration or insider threats. If confirmed malicious, an attacker could use this method to exfiltrate sensitive information, leading to data breaches and compliance violations.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0046
This analytic detects email files (.pst or .ost) being created outside the standard Outlook directories. This activity is significant as it may indicate data exfiltration or unauthorized access to email data. If confirmed malicious, an attacker could potentially access sensitive email content, leading to data breaches or further exploitation within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1045
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
The analytic identifies a significant increase in data transfers from an email server to client hosts. It uses statistical analysis on network traffic to detect anomalies based on average and standard deviation of outbound bytes. This activity is significant as it may indicate a malicious actor exfiltrating data via the email server, potentially leading to unauthorized data access and breaches.
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
This analytic detects excessive usage of the nslookup application, which may indicate potential DNS exfiltration attempts. It monitors process executions, specifically focusing on nslookup.exe, and identifies outliers by comparing the frequency of nslookup executions against a calculated threshold. This activity is significant as it can reveal attempts by malware or APT groups to exfiltrate data via DNS queries. If confirmed malicious, this behavior could allow attackers to stealthily transfer sensitive information out of the network, bypassing traditional data exfiltration defenses.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0043
The analytic identifies hosts receiving an unusually high volume of network traffic from an email server. It leverages the Network_Traffic data model to sum incoming bytes to clients from email servers, comparing current traffic against historical averages and standard deviations. This activity is significant as it may indicate data exfiltration by a malicious actor using the email server. If confirmed malicious, this could lead to unauthorized data access and potential data breaches, compromising sensitive information and impacting organizational security.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0042
The analytic identifies spikes in the number of Server Message Block (SMB) connections using the Machine Learning Toolkit (MLTK). It leverages the Network_Traffic data model to monitor SMB traffic on ports 139 and 445, applying a machine learning model to detect anomalies. Sudden increases in SMB traffic can indicate lateral movement or data exfiltration attempts by attackers. If confirmed malicious, this behavior could lead to unauthorized access, data theft, or further compromise of the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0042
The analytic identifies successful access to an S3 bucket from a new or previously unseen remote IP address. This activity is significant because access from unfamiliar IP addresses could indicate unauthorized access or potential data exfiltration attempts. If confirmed malicious, this activity could lead to unauthorized data access, data theft, or further exploitation of the compromised S3 bucket, posing a significant risk to sensitive information stored within the bucket.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1041
This analytic detects when Microsoft Office 365 Data Loss Prevention (DLP) rules have been triggered. DLP rules are configured for security, regulatory, or business compliance reasons. Detections from this analytic should be thoroughly evaluated to determine the security relevance of the underlying DLP events. The accuracy of this analytic depends on the upstream DLP configuration.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1041
This analytic detects the execution of a renamed `rclone.exe` process, which is commonly used for data exfiltration to remote destinations. This detection leverages Endpoint Detection and Response (EDR) telemetry, focusing on process names and original file names that do not match. This activity is significant because ransomware groups often use RClone to exfiltrate sensitive data. If confirmed malicious, this behavior could indicate an ongoing data exfiltration attempt, potentially leading to significant data loss and further compromise of the affected systems.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2041
The analytic detects suspicious modifications to AWS AMI attributes, such as sharing an AMI with another AWS account or making it publicly accessible. It leverages AWS CloudTrail logs to identify these changes by monitoring specific API calls. This activity is significant because adversaries can exploit these modifications to exfiltrate sensitive data stored in AWS resources. If confirmed malicious, this could lead to unauthorized access and potential data breaches, compromising the confidentiality and integrity of organizational information.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0040
The following analytic identifies when an O365 email account sends an excessive number of email attachments to external recipients within a short period (within 1 hour). This behavior may indicate a compromised account where the threat actor is attempting to exfiltrate data from the mailbox. Threat actors may attempt to transfer data through email as a simple means of exfiltration 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
0040
The analytic identifies Domain Generation Algorithm (DGA) generated domains using a pre-trained deep learning model. It leverages network resolution data to analyze domain names and detect unusual character sequences indicative of DGA activity. Adversaries often use DGAs to generate numerous domain names for command-and-control servers, making it harder to block malicious traffic. If confirmed malicious, this activity could enable attackers to maintain persistent communication with compromised systems, evade detection, and execute further malicious actions.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1040
This analytic identifies significant changes in network communication behavior within Kubernetes containers by examining the inbound to outbound network IO ratios. It leverages process metrics from an OTEL collector and Kubelet Stats Receiver, along with data from Splunk Observability Cloud. Anomalies are detected using a lookup table containing average and standard deviation values for network IO, triggering an event if the anomaly persists for over an hour. This activity is significant as it may indicate data exfiltration, command and control communication, or compromised container behavior. If confirmed malicious, it could lead to data breaches, service outages, and unauthorized access within the Kubernetes cluster.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
The following analytic detects instances where a user has initiated an eDiscovery search or exported a PST file in an Office 365 environment. It leverages Office 365 management activity logs, specifically filtering for events under ThreatManagement with the name "eDiscovery search started or exported." This activity is significant as it may indicate data exfiltration attempts or unauthorized access to sensitive information. If confirmed malicious, it suggests an attacker or insider threat is attempting to gather or exfiltrate data, potentially leading to data breaches, loss of intellectual property, or unauthorized access to confidential communications. Immediate investigation is required.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0039
The analytic detects the use of the curl command with specific switches (-F, --form, --upload-file, -T, -d, --data, --data-raw, -I, --head) to upload AWS credentials or configuration files to a remote destination. This detection 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 exfiltrate sensitive AWS credentials, a technique known to be used by the TeamTNT group. If confirmed malicious, this could lead to unauthorized access and potential compromise of AWS resources.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0038
This analytic detects a Windows application establishing an SMTP connection from a non-common installation path. It leverages Sysmon EventCode 3 to identify processes not typically associated with email clients (e.g., Thunderbird, Outlook) making SMTP connections. This activity is significant as adversaries, including malware like AgentTesla, use such connections for Command and Control (C2) communication to exfiltrate stolen data. If confirmed malicious, this behavior could lead to unauthorized data exfiltration, including sensitive information like desktop screenshots, browser data, and system details, compromising the affected host.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0038
The analytic identifies the creation of AWS Batch jobs that could potentially abuse the AWS Bucket Replication feature on S3 buckets. It leverages AWS CloudTrail logs to detect the `JobCreated` event, analyzing job details and their status. This activity is significant because attackers can exploit this feature to exfiltrate data by creating malicious batch jobs. If confirmed malicious, this could lead to unauthorized data transfer between S3 buckets, resulting in data breaches and loss of sensitive information.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0037
The analytic identifies when the results of a content search within the Office 365 Security and Compliance Center are exported. It uses the SearchExported operation from the SecurityComplianceCenter workload in the o365_management_activity data source. This activity is significant because exporting search results can involve sensitive or critical organizational data, potentially leading to data exfiltration. If confirmed malicious, an attacker could gain access to and exfiltrate sensitive information, posing a severe risk to the organization's data security and compliance posture.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0037
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