Splunk Security

@SplunkSecurity
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2,505 detections

The following analytic detects the use of the Background Intelligent Transfer Service (BITS) client application in allowed outbound connections. It leverages logs from Cisco Secure Firewall Threat Defense devices and identifies instances where BITS is used to initiate downloads from non-standard or unexpected domains. While BITS is a legitimate Windows service used for downloading updates, it is also commonly abused by adversaries to stealthily retrieve payloads or tools. This analytic filters out known Microsoft Edge update URLs and focuses on connections that may indicate suspicious or unauthorized file transfers. If confirmed malicious, this could represent a command and control (C2) channel or a download of malware or tooling as part of an attack chain.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0034
This analytic processes and enriches alerts from CrowdStrike Falcon Event Stream, specifically `DetectionSummaryEvent` and `IdpDetectionSummaryEvent`. It normalizes fields such as user, destination, severity, and MITRE ATT&CK information. The rule dynamically generates drilldown links and constructs a descriptive title and message for each alert. It is designed to provide a standardized view of various CrowdStrike detections, including NGAV, Intel Detection, and Identity Protection alerts, ensuring proper risk scoring and analyst queue population.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0051
The analytic identifies instances where the Windows Explorer process (explorer.exe) is executed with a URL in its command line. This behavior is uncommon and suspicious, as adversaries may abuse explorer.exe to open URLs with the default browser to download and execute malicious payloads. This detection leverages process execution logs from EDR agents.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0043
The following analytic detects instances of DLLHost.exe running without command line arguments while establishing a network connection. This behavior is identified using Endpoint Detection and Response (EDR) telemetry, focusing on process execution and network activity data. It is significant because DLLHost.exe typically runs with specific arguments, and its absence can indicate malicious activity, such as Cobalt Strike usage. If confirmed malicious, this activity could allow attackers to execute code, move laterally, or exfiltrate data, posing a severe threat to the network's security.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1039
This analytic identifies a suspicious process that is recursively deleting executable files on a compromised host. It leverages Sysmon Event Codes 23 (File Delete) and 26 (File Delete logged) to detect this activity by monitoring for a high volume of deletions or overwrites of files with extensions like .exe, .sys, and .dll within a short timeframe. This behavior is significant as it is commonly associated with destructive malware such as CaddyWiper, DoubleZero, and SwiftSlicer, which aim to make file recovery impossible. If confirmed malicious, this activity could lead to significant data loss and system instability, severely impacting business operations.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0046
This detection leverages Azure Graph activity logs to identify when Graph APIs have been used to identify 10 or more service principals. This type of behavior is associated with tools such as Azure enumeration tools like AzureHound or ROADtools.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
40105
This detection identifies the presence of the default AzureHound user-agent string within Microsoft Graph Activity logs and NonInteractive SignIn Logs. AzureHound is a tool used for gathering information about Azure Active Directory environments, often employed by security professionals for legitimate auditing purposes. However, it can also be leveraged by malicious actors to perform reconnaissance activities, mapping out the Azure AD infrastructure to identify potential vulnerabilities and targets for further exploitation. Detecting its usage can help in identifying unauthorized access attempts and preemptively mitigating potential security threats to your Azure environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0080
The following analytic identifies anomalous GetObject API activity in AWS, indicating potential data exfiltration attempts. It leverages AWS CloudTrail logs and uses the `anomalydetection` command to detect unusual patterns in the frequency of GetObject API calls by analyzing fields such as "count," "user_type," and "user_arn" within a 10-minute window. This activity is significant as it may indicate unauthorized data access or exfiltration from S3 buckets. If confirmed malicious, attackers could exfiltrate sensitive data, leading to data breaches and compliance violations.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
3057
The following analytic detects the suspicious add user account type. 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
0032
This analytic detects the use of the Certify tool via an in-memory PowerShell function to enumerate Active Directory Certificate Services (AD CS) environments. It leverages PowerShell Script Block Logging (EventCode 4104) to identify specific command patterns associated with Certify's enumeration and exploitation functions. This activity is significant as it indicates potential reconnaissance or exploitation attempts against AD CS, which could lead to unauthorized certificate issuance. If confirmed malicious, attackers could leverage this to escalate privileges, persist in the environment, or access sensitive information by abusing AD CS.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2053
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