Splunk Security

@SplunkSecurity
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2,496 detections

The analytic identifies instances where a service principal in Azure Active Directory assigns app roles without standard admin consent. This activity is detected by analyzing Entra ID logs from the `azure_monitor_aad` data source, specifically looking for "Add app role assignment to service principal" or "Add member to role*" operations initiated by a service principal. This detection is crucial for identifying potential bypasses of administrative consent processes, which could lead to unauthorized privilege grants. If malicious, this could allow attackers to exploit automation to assign sensitive permissions without proper oversight, compromising the security of the Azure AD environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
1083
The following analytic detects the creation of files typically associated with SharpHound, a reconnaissance tool used for gathering domain and trust data. It leverages file modification events from the Endpoint.Filesystem data model, focusing on default file naming patterns like `*_BloodHound.zip` and various JSON files. This activity is significant as it indicates potential domain enumeration, which is a precursor to more targeted attacks. If confirmed malicious, an attacker could gain detailed insights into the domain structure, facilitating lateral movement and privilege escalation.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
1082
This analytic detects executable files (.exe or .dll) being written to Windows administrative SMB shares (Admin$, IPC$, C$). This behavior is significant as it is commonly used by tools like PsExec/PaExec for staging binaries before creating and starting services on remote endpoints, a technique often employed for lateral movement and remote code execution. If confirmed malicious, this activity could allow an attacker to execute arbitrary code remotely, potentially compromising additional systems within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
2082
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
2 years 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
2 years ago
1081
This analytic identifies the creation or modification of email inbox rules within an Office 365 environment. It specifically looks for `New-InboxRule` and `Set-InboxRule` operations in the O365 management activity logs where the rule parameters indicate actions such as mail forwarding (`ForwardTo`, `ForwardAsAttachmentTo`, `RedirectTo`), or mail manipulation like deletion (`SoftDeleteMessage`, `DeleteMessage`) or moving to specific folders (`MoveToFolder`, `CopyToFolder`). While legitimate users create inbox rules, adversaries often leverage these techniques to exfiltrate emails, maintain persistence, or hide their activities by deleting or moving security alerts.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
1081
This analytic detects a single source computer accessing Windows administrative shares (C$, Admin$, IPC$) on 30 or more remote endpoints within a 5-minute window. It leverages Windows Event IDs 5140 and 5145, which are generated for file share events. This behavior is significant as it may indicate an adversary enumerating network shares to locate sensitive files, a common tactic used by threat actors for reconnaissance and lateral movement. If confirmed malicious, this activity could lead to unauthorized access to critical data, lateral movement, and potential compromise of multiple systems within the network.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
2 years ago
1081
The analytic detects the use of .NET classes in PowerShell to download a URL payload directly into memory, a common fileless malware staging technique. It leverages PowerShell Script Block Logging (EventCode=4104) to identify suspicious PowerShell commands involving `system.net.webclient`, `system.net.webrequest`, and `IO.MemoryStream`. This activity is significant as it indicates potential fileless malware execution, which is harder to detect and can bypass traditional file-based defenses. If confirmed malicious, this technique could allow attackers to execute code in memory, evade detection, and maintain persistence in the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
2 years ago
2080
The analytic identifies a statistically significant increase in access to Active Directory objects, which may indicate attacker enumeration. It leverages Windows Security Event Code 4662 to monitor and analyze access patterns, comparing them against historical averages to detect anomalies. This activity is significant for a SOC because abnormal access to AD objects can be an early indicator of reconnaissance efforts by an attacker. If confirmed malicious, this behavior 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
1079
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
avatar
Splunk Security Content
2 years ago
6079
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