Splunk Security

@SplunkSecurity
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2,515 detections

The analytic detects a process attempting to access winlogon.exe to duplicate its handle. This is identified using Sysmon EventCode 10, focusing on processes targeting winlogon.exe with specific access rights (0x1040). This activity is significant because it is a common technique used by adversaries to escalate privileges by leveraging the high privileges and security tokens associated with winlogon.exe. If confirmed malicious, this could allow an attacker to gain elevated privileges, potentially leading to full system compromise and unauthorized access to sensitive information.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0031
The following analytic identifies the execution of the legacy `auditpol.exe` included with the Windows 2000 Resource Kit Tools, with the "/disable" command-line argument or one of the allowed category flags and the "none" option, in order to disable a specific logging category from the audit policy. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity can be significant as it indicates potential defense evasion by adversaries or Red Teams, aiming to limit data that can be leveraged for detections and audits. If confirmed malicious, this behavior could allow attackers to bypass defenses, and plan further attacks, potentially leading to full machine compromise or lateral movement.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0031
The following analytic identifies the execution of `auditpol.exe` with the "/set" flag, and "/sd" command-line arguments used to modify the security descriptor of the audit policy. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity can be significant as it indicates potential defense evasion by adversaries or Red Teams, aiming to limit data that can be leveraged for detections and audits. An attacker, can disable certain policy categories from logging and then change the security descriptor in order to restrict access to certain users or application from reverting their changes. If confirmed malicious, this behavior could allow attackers to bypass defenses, and plan further attacks, potentially leading to full machine compromise or lateral movement.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
1031
This analytic detects the use of the sfc.exe utility with the "-unblock" parameter, a feature within Cisco Secure Endpoint. The "-unblock" flag is used to remove system blocks imposed by the endpoint protection. This detection focuses on command-line activity that includes the "-unblock" parameter, as it may indicate an attempt to restore access to files or processes previously blocked by the security software. While this action could be legitimate in troubleshooting scenarios, malicious actors might use it to override protective measures, enabling execution of blocked malicious payloads or bypassing other security mechanisms.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0031
The following analytic detects modifications to default Group Policy Objects (GPOs) using the Group Policy Management Editor (GPME). It leverages the Endpoint data model to identify processes where `mmc.exe` executes `gpme.msc` with specific GUIDs related to default GPOs. This activity is significant because default GPOs, such as the `Default Domain Controllers Policy` and `Default Domain Policy`, are critical for enforcing security policies across the domain. If malicious, such modifications could allow an attacker to gain further access, establish persistence, or deploy malware across numerous hosts, severely compromising the network's security.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0031
The analytic detects the modification of the Windows Registry key "DisableAntiSpyware" being set to disable. This activity is significant as it is commonly associated with Ryuk ransomware infections, indicating potential malicious intent to disable Windows Defender. If confirmed malicious, this action could allow attackers to disable critical security defenses, facilitating further malicious activities such as data encryption, exfiltration, or additional system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0031
The analytic detects instances where file or folder permissions are modified to grant read-only access using `icacls.exe`, `cacls.exe`, or `xcacls.exe`. These changes are characterized by the presence of read-related permissions (e.g., R, REA, RA, RD) and the absence of write (W) or execute (E) permissions. Monitoring these events is crucial for tracking access control changes that could be intentional for restricting access or indicative of malicious behavior. Alerts generated by this detection help ensure that legitimate security measures are enforced while unauthorized changes are promptly investigated.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0031
The analytic detects the execution of the `Get-DomainOU` cmdlet, which is part of the PowerView toolkit. This cmdlet is used for Windows domain enumeration, specifically to gather information about organizational units within Active Directory. Adversaries may use this to map the domain structure, aiding in further exploitation, lateral movement, or privilege escalation. The detection leverages PowerShell Script Block Logging (EventCode=4104).
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0031
The following analytic detects modifications to the Windows registry that change the Windows Defender Quick Scan Interval. It leverages data from the Endpoint.Registry data model, focusing on changes to the "QuickScanInterval" registry path. This activity is significant because altering the scan interval can impair Windows Defender's ability to detect malware promptly, potentially allowing threats to persist undetected. If confirmed malicious, this modification could enable attackers to bypass security measures, maintain persistence, and execute further malicious activities without being detected by quick scans.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0031
The following analytic detects modifications to the Windows registry that disable the Windows Defender SmartScreen App Install Control feature. It leverages data from the Endpoint.Registry data model to identify changes to specific registry values. This activity is significant because disabling App Install Control can allow users to install potentially malicious web-based applications without restrictions, increasing the risk of security vulnerabilities. If confirmed malicious, this action could lead to the installation of harmful applications, potentially compromising the system and exposing sensitive information.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0031
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