Detections

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

2,146 detections

This analytic identifies Snort intrusion signatures that have been triggered by ten or more distinct internal IP addresses within a one-hour window. It leverages Cisco Secure Firewall Threat Defense logs and focuses on the IntrusionEvent event type to detect activity that may indicate broad targeting or mass exploitation attempts. This behavior is often associated with opportunistic scanning, worm propagation, or automated exploitation of known vulnerabilities across multiple systems. If confirmed malicious, this could represent the early phase of a coordinated attack aiming to gain a foothold on several hosts or move laterally across the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
6079
The following analytic identifies suspicious command-line parameters associated with the use of Impacket's smbexec.py for lateral movement. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on specific command-line patterns indicative of Impacket tool usage. This activity is significant as both Red Teams and adversaries use Impacket for remote code execution and lateral movement. If confirmed malicious, this activity could allow attackers to execute commands on remote endpoints, potentially leading to unauthorized access, data exfiltration, or further compromise of the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
4076
This analytic identifies unexpected Active Directory replication traffic originating from non-domain controller sources. It specifically looks for network traffic associated with AD replication protocols (ms-dc-replication, drsr, ad drs). Such traffic should typically only occur between legitimate domain controllers. Detection of this activity from other sources may indicate malicious activities like DCSync or DCShadow, which are commonly used for credential dumping and could lead to unauthorized access and potential domain-wide compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
3073
The following analytic identifies excessive AccessDenied events within an hour timeframe for IAM users in AWS. It leverages AWS CloudTrail logs to detect multiple failed access attempts from the same source IP and user identity. This activity is significant as it may indicate that an access key has been compromised and is being misused for unauthorized discovery actions. If confirmed malicious, this could allow attackers to gather information about the AWS environment, potentially leading to further exploitation or privilege escalation.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2066
The following analytic identifies potential DNS data exfiltration using a pre-trained deep learning model. It leverages DNS request data from the Network Resolution datamodel and computes features from past events between the same source and domain. The model generates a probability score (pred_is_exfiltration_proba) indicating the likelihood of data exfiltration. This activity is significant as DNS tunneling can be used by attackers to covertly exfiltrate sensitive data. If confirmed malicious, this could lead to unauthorized data access and potential data breaches, compromising the organization's security posture.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2064
The analytic identifies web activity related to employment searches within a network using Zscaler web proxy logs. It focuses on entries categorized as 'Job/Employment Search' and analyzes data points such as device owner, user, URL category, destination URL, and IP. This detection helps monitor potential insider threats by identifying users who may be seeking new employment, which could indicate a risk of data exfiltration or other insider threats, potentially leading to sensitive information leakage or other security breaches.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0064
The analytic identifies spikes in blocked outbound network connections originating from within an AWS environment. It uses VPC Flow Logs data from CloudWatch, specifically looking for 'blocked' actions from internal IP ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) to external destinations. A spike is determined by comparing the current number of blocked connections against a calculated baseline (average and standard deviation) over time. This detection is significant as it can indicate potential exfiltration attempts or misconfigurations leading to data leakage. If confirmed malicious, such activity could allow attackers to bypass network defenses, leading to unauthorized data transfer or communication with malicious external entities.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
3062
The analytic detects an Azure AD account with concurrent sessions originating from multiple unique IP addresses within a 5-minute window. It leverages Azure Active Directory NonInteractiveUserSignInLogs to identify this behavior by analyzing successful authentication events and counting distinct source IPs. This activity is significant as it may indicate session hijacking, where an attacker uses stolen session cookies to access corporate resources from a different location. If confirmed malicious, this could lead to unauthorized access to sensitive information and potential data breaches.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2061
The following analytic detects suspicious database file and directory discovery activities, which may signal an attacker attempt to locate and assess critical database assets on a compromised system. This behavior is often a precursor to data theft, unauthorized access, or privilege escalation, as attackers seek to identify valuable information stored in databases. By monitoring for unusual or unauthorized attempts to locate database files and directories, this analytic aids in early detection of potential reconnaissance or data breach efforts, enabling security teams to respond swiftly and mitigate the risk of further compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0060
The analytic detects local file inclusion (LFI) attacks targeting Kubernetes Nginx ingress controllers. It leverages Kubernetes logs, parsing fields such as `request` and `status` to identify suspicious patterns indicative of LFI attempts. This activity is significant because LFI attacks can allow attackers to read sensitive files from the server, potentially exposing critical information. If confirmed malicious, this could lead to unauthorized access to sensitive data, further exploitation, and potential compromise of the Kubernetes environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0058
The analytic identifies AWS console login attempts by users from a new region. It leverages AWS CloudTrail events and compares current login regions against a baseline of previously seen regions for each user. This activity is significant as it may indicate unauthorized access attempts or compromised credentials. If confirmed malicious, an attacker could gain unauthorized access to AWS resources, potentially leading to data breaches, resource manipulation, or further lateral movement within the cloud environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0057
This analytic detects file transfers flagged as malware that occurred over non-standard ports (other than 80 and 443) from Cisco Secure Firewall Threat Defense logs. Adversaries may attempt to bypass protocol-based detection or use alternate ports to blend in with other traffic. This analytic identifies these non-conventional flows and surfaces potential evasion techniques. If confirmed malicious, this indicates potential malware delivery or other nefarious activity.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2057
The analytic detects path traversal command-line execution, often used in malicious documents to execute code via msdt.exe for defense evasion. It leverages Endpoint Detection and Response (EDR) data, focusing on specific patterns in process paths. This activity is significant as it can indicate an attempt to bypass security controls and execute unauthorized code. If confirmed malicious, this behavior could lead to code execution, privilege escalation, or persistence within the environment, potentially allowing attackers to deploy malware or leverage other living-off-the-land binaries (LOLBins).
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0056
The following analytic detects `spoolsv.exe` writing a `.dll` file, which is unusual behavior and may indicate exploitation of vulnerabilities like CVE-2021-34527 (PrintNightmare). This detection leverages Sysmon EventID 11 to monitor file creation events in the `\spool\drivers\x64\` directory. This activity is significant because `spoolsv.exe` typically does not write DLL files, and such behavior could signify an ongoing attack. If confirmed malicious, this could allow an attacker to execute arbitrary code, escalate privileges, or maintain persistence on the compromised system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0055
The analytic identifies excessive DNS query failures by counting DNS responses that do not indicate success, triggering when there are more than 50 occurrences. It leverages the Network_Resolution data model, focusing on DNS reply codes that signify errors. This activity is significant because a high number of DNS failures can indicate potential network misconfigurations, DNS poisoning attempts, or malware communication issues. If confirmed malicious, this activity could lead to disrupted network services, hindered communication, or data exfiltration attempts by attackers.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0055
The following analytic detects a suspicious registry modification aimed at disabling security audit logs by adding a specific registry entry. It leverages data from the Endpoint.Registry data model, focusing on changes to the "Control\\MiniNt" registry path. This activity is significant because it can prevent Windows from logging any events to the Security Log, effectively blinding security monitoring efforts. If confirmed malicious, this technique could allow an attacker to operate undetected, making it difficult to trace their actions and compromising the integrity of security audits.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0054
The analytic identifies blocked destinations within a network that are deemed privacy risks by Zscaler. It leverages web proxy logs, focusing on entries marked as "Privacy Risk." Key data points such as device owner, user, URL category, destination URL, and IP are analyzed. This activity is significant for a SOC as it helps monitor and manage privacy risks, ensuring a secure network environment. If confirmed malicious, this activity could indicate attempts to access or exfiltrate sensitive information, posing a significant threat to data privacy and security.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0053
The following analytic identifies high inbound or outbound network I/O anomalies in Kubernetes containers. It leverages process metrics from an OTEL collector and Kubelet Stats Receiver, along with data from Splunk Observability Cloud. A lookup table with average and standard deviation values for network I/O is used to detect anomalies persisting over a 1-hour period. This activity is significant as it may indicate data exfiltration, command and control communication, or unauthorized data transfers. If confirmed malicious, it could lead to data breaches, service outages, financial losses, and reputational damage.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0051
This analytic detects the use of `mavinject.exe` for DLL injection into running processes. It specifically looks for command-line parameters such as `/INJECTRUNNING` and `/HMODULE`. This activity indicates potential arbitrary code execution, a common tactic for malware deployment and persistence. If confirmed malicious, this could allow attackers to execute unauthorized code, escalate privileges, and maintain persistence within the environment, posing a severe security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0051
This analytic detects the execution of AdvancedRun.exe, a utility that allows users to run programs with different administrative privileges, user accounts, or environment settings. It identifies the process by its name or original file name and flags common command-line arguments often used for configuration or specific execution parameters. Monitoring this activity is crucial as AdvancedRun can be leveraged by attackers for remote code execution, privilege escalation, or maintaining persistence within an environment, similar to tools like PsExec. If used maliciously, it could enable the execution of arbitrary commands or configuration-based automation.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0051
The analytic detects multiple CrowdStrike LOW severity alerts originating from the same endpoint, indicating a series of minor suspicious activities or policy violations. Specifically, it triggers when an endpoint generates three or more distinct types of LOW severity alerts. These alerts are not immediately critical but should be reviewed to prevent potential threats. They often highlight unusual behavior or low-level risks that, if left unchecked, could escalate into more significant security issues. Regular monitoring and analysis of these alerts are essential for maintaining robust security, as a cluster of different low-severity events can be an early indicator of a more significant compromise or an adversary's reconnaissance activities.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1049
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