Detections

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

247 detections

'This query identifies exploitation attempts using Pulse Connect Secure(PCS) vulnerability (CVE-2021-22893) to the VPN server'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0014
The following analytic detects attempts to stop a service on Linux systems. It leverages data from Linux Auditd. This activity is significant as adversaries often stop or 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
0054
The following analytic detects the suspicious auditd service stop. This behavior is critical for a SOC to monitor because it may indicate attempts to gain unauthorized access or maintain control over a system. Such actions could be signs of malicious activity. If confirmed, this could lead to serious consequences, including a compromised system, unauthorized access to sensitive data, or even a wider breach affecting the entire network. Detecting and responding to these signs early is essential to prevent potential security incidents.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0051
The analytic detects cloud API calls executed by user roles that have not previously run these commands. It leverages the Change data model in Splunk to identify commands executed by users with the user_type of AssumedRole and a status of success. This activity is significant because new commands from different user roles can indicate potential malicious activity or unauthorized actions. If confirmed malicious, this behavior could lead to unauthorized access, data breaches, or other damaging outcomes by exploiting new or unmonitored commands within the cloud environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1067
The analytic detects the creation of cloud compute instances using previously unseen image IDs. It leverages cloud infrastructure logs to identify new image IDs that have not been observed before. This activity is significant because it may indicate unauthorized or suspicious activity, such as the deployment of malicious payloads or unauthorized access to sensitive information. If confirmed malicious, this could lead to data breaches, unauthorized access, or further compromise of the cloud environment. Immediate investigation is required to determine the legitimacy of the instance creation and to mitigate potential threats.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0067
The following analytic detects the suspicious sysmon service stop. This behavior is critical for a SOC to monitor because it may indicate attempts to gain unauthorized access or maintain control over a system. Such actions could be signs of malicious activity. If confirmed, this could lead to serious consequences, including a compromised system, unauthorized access to sensitive data, or even a wider breach affecting the entire network. Detecting and responding to these signs early is essential to prevent potential security incidents.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0036
This rule detects when a network connection is made to a domain that has expired. It leverages WHOIS data to identify domains whose expiration time is before the event timestamp. The rule specifically looks for HTTP network events and joins them with WHOIS information to identify access to recently expired domains. This could indicate access to potentially malicious infrastructure, as expired domains can be re-registered by threat actors for nefarious purposes.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
1 year ago
0034
This analytic identifies high-severity intrusion events based on the classification assigned to Snort rules within Cisco Secure Firewall logs. It leverages Cisco Secure Firewall Threat Defense logs and focuses on events classified as: A Network Trojan was Detected, Successful Administrator Privilege Gain, Successful User Privilege Gain, Attempt to Login By a Default Username and Password, Known malware command and control traffic, Known malicious file or file based exploit, Known client side exploit attempt, Large Scale Information Leak. These classifications typically represent significant threats such as remote code execution, credential theft, lateral movement, or malware communication. Detection of these classifications should be prioritized for immediate investigation.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
110132
This analytic detects Lumma Stealer download attempts using Cisco Secure Firewall Intrusion Events. It leverages Cisco Secure Firewall Threat Defense IntrusionEvent logs to identify cases where Snort signatures with specific IDs have been triggered. If confirmed malicious, this behavior could indicate an active infection of Lumma Stealer.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
3043
Detects changes to the ESXi syslog configuration via the 'esxcli' command-line utility. This activity could indicate an adversary attempting to impair defenses by modifying logging configurations on an ESXi hypervisor.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
1023
This analytic aggregates and summarizes alerts from Microsoft Defender for Endpoint. It extracts details such as source, file name, severity, process command line, IP address, registry key, signature, description, and unique ID. The detection is not intended to identify new activity from raw data but rather to leverage existing Microsoft Defender for Endpoint alerts for correlation and risk-based alerting. It filters out alerts with a 'clean' verdict and dynamically maps MITRE techniques and assigns risk scores based on the alert's severity.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
10269
This analytic detects potentially suspicious large outbound data transfers from internal to external networks using Cisco Secure Firewall Threat Defense logs. It calculates the total volume of data exchanged per connection by summing InitiatorBytes and ResponderBytes. Connections exceeding 100 MB are flagged, as these may indicate unauthorized data exfiltration, especially if initiated by unusual users, hosts, or processes. The detection is scoped to inside-to-outside network flows. If confirmed malicious, this behavior may reflect data staging and exfiltration over an encrypted or stealthy transport.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
4084
The following analytic identifies when a new device is enrolled on an Okta account. It uses OktaIm2 logs ingested via the Splunk Add-on for Okta Identity Cloud to detect the creation of new device enrollments. This activity is significant as it may indicate a legitimate user settinging up a new device or an adversary adding a device to maintain unauthorized access. If confirmed malicious, this could lead to potential account takeover, unauthorized access, and persistent control over the compromised Okta account. Monitoring this behavior is crucial for detecting and mitigating unauthorized access attempts.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
3081
This correlation rule identifies when a user exceeds a predefined risk threshold based on multiple suspicious Okta activities within a 24-hour period. It aggregates risk events from "Suspicious Okta Activity," "Okta Account Takeover," and "Okta MFA Exhaustion" analytic stories. The detection is significant as it highlights potentially compromised user accounts exhibiting multiple tactics, techniques, and procedures (TTPs). If confirmed malicious, this activity could indicate a serious security breach, allowing attackers to gain unauthorized access, escalate privileges, or persist within the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1081
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
The analytic detects the execution of `pkexec` without any command-line arguments. This behavior leverages data from Endpoint Detection and Response (EDR) agents, focusing on process telemetry. The significance lies in the fact that this pattern is associated with the exploitation of CVE-2021-4034 (PwnKit), a critical vulnerability in Polkit's pkexec component. If confirmed malicious, this activity could allow an attacker to gain full root privileges on the affected Linux system, leading to complete system compromise and potential unauthorized access to sensitive information.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0072
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 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 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
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