Splunk Security

@SplunkSecurity
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2,496 detections

The following analytic detects an application attempting to connect and create an ADSI object to perform an LDAP query. It leverages Sysmon EventCode 11 to identify changes in the Active Directory Schema cache files located in %LOCALAPPDATA%\Microsoft\Windows\SchCache or %systemroot%\SchCache. This activity is significant as it can indicate the presence of suspicious applications, such as ransomware, using ADSI object APIs for LDAP queries. If confirmed malicious, this behavior could allow attackers to gather sensitive directory information, potentially leading to further exploitation or lateral movement within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0028
This analytic detects a sharp increase in the number of files written to a specific host. It leverages the Endpoint.Filesystem data model, focusing on 'created' actions and comparing current file write counts against historical averages and standard deviations. This activity is significant as a sudden spike in file writes can indicate malicious activities such as ransomware encryption or data exfiltration. If confirmed malicious, this behavior could lead to significant data loss, system compromise, or further propagation of malware within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0028
The following analytic identifies the execution of the dxdiag.exe process with specific command-line arguments, which is used to gather system information. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process creation events and command-line details. This activity is significant because dxdiag.exe is rarely used in corporate environments and its execution may indicate reconnaissance efforts by malicious actors. If confirmed malicious, this activity could allow attackers to collect detailed system information, aiding in further exploitation or lateral movement within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0028
The analytic identifies unusually long command lines executed on hosts, which may indicate malicious activity. It leverages the Machine Learning Toolkit (MLTK) to detect command lines with lengths that deviate from the norm for a given user. This is significant for a SOC as unusually long command lines can be a sign of obfuscation or complex malicious scripts. If confirmed malicious, this activity could allow attackers to execute sophisticated commands, potentially leading to unauthorized access, data exfiltration, or further compromise of the system.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0028
The following analytic detects the spawning of cmd or PowerShell processes by the wermgr.exe process. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process telemetry, including parent-child process relationships and command-line executions. This behavior is significant as it is commonly associated with code injection techniques used by malware like TrickBot to execute shellcode or malicious DLL modules. If confirmed malicious, this activity could allow attackers to execute arbitrary code, escalate privileges, or maintain persistence within the environment, posing a severe threat to system security.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0028
The analytic identifies the execution of `auditpol.exe` with the "/set" and "/exclude" command-line arguments. This indicates that a user's per-user policy will suppress auditing regardless of the system audit policy. This activity can be significant as it indicates potential defense evasion by adversaries or Red Teams, aiming to exclude specific user events from log data. 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
0028
The analytic identifies the execution of the "ipconfig /displaydns" command, which retrieves DNS reply information using the built-in Windows tool IPConfig. Monitoring this activity is significant as threat actors and post-exploitation tools like WINPEAS often abuse this command to gather network information. If confirmed malicious, this activity could allow attackers to map the network, identify DNS servers, and potentially facilitate further network-based attacks or lateral movement.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0028
The analytic identifies a source user failing to authenticate with multiple users using explicit credentials on a host. It leverages Windows Event Code 4648 and calculates the standard deviation for each host, using the 3-sigma rule to detect anomalies. This behavior is significant as it may indicate a Password Spraying attack, where an adversary attempts to gain initial access or elevate privileges. If confirmed malicious, this activity could lead to unauthorized access, privilege escalation, or further compromise of the Active Directory environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0028
The following analytic identifies a source process failing to authenticate multiple users, potentially indicating a Password Spraying attack. It leverages Windows Event 4625, which logs failed logon attempts, and uses statistical analysis to detect anomalies. This activity is significant as it may represent an adversary attempting to gain initial access or elevate privileges within an Active Directory environment. If confirmed malicious, the attacker could compromise multiple accounts, leading to unauthorized access, data exfiltration, or further lateral movement within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
0028
The analytic identifies a source endpoint failing to authenticate multiple valid users using the NTLM protocol, potentially indicating a Password Spraying attack. It leverages Event 4776 from Domain Controllers, calculating the standard deviation for each host and applying the 3-sigma rule to detect anomalies. This activity is significant as it may represent an adversary attempting to gain initial access or elevate privileges. If confirmed malicious, the attacker could compromise multiple accounts, leading to unauthorized access and potential lateral movement within the network.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
2 years ago
0028
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