Detections

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

3,613 detections

Yara rule that detects Skuld infostealer.
ReversingLabs Yara@ReversingLabsYara
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ReversingLabs Yara
1 year ago
000
This rule detects the launch of web browsers (both Chromium-based and Firefox) with command-line arguments that enable remote debugging. This functionality, while legitimate for developers, can be abused by attackers to inject malicious code, steal credentials, or perform browser session hijacking. The rule specifically looks for '--remote-debugging-' in Chromium-based browsers and '-start-debugger-server' in Firefox.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
3146
Detects "BugCheck" errors indicating the system rebooted due to a crash, capturing the bugcheck code, dump file path, and report ID. This event can be leveraged by adversaries to obtain crash dumps which may contain sensitive information, including credentials.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0023
This rule detects the execution of common archiving utilities (zip, gzip, tar) on Linux systems. Adversaries often compress data prior to exfiltration to reduce its size and make it easier to transfer. This rule specifically looks for the 'execve' system call with 'zip', 'gzip -k', or 'tar -c' as the primary command and arguments.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
2026
Detects suspicious commands as identified in CISA Living off the Land pdf. Alone they may be normal but in concert, they may be worth looking into
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
1 year ago
000
Detects the enabling of the "EnablePeriodicBackup" registry value. Once enabled, The OS will backup System registry hives on restarts to the "C:\Windows\System32\config\RegBack" folder. Windows creates a "RegIdleBackup" task to manage subsequent backups. Registry backup was a default behavior on Windows and was disabled as of "Windows 10, version 1803". Adversaries might enable this feature to collect system registry hives, which can contain sensitive information.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0014
Detects "BugCheck" errors indicating the system rebooted due to a crash, capturing the bugcheck code, dump file path, and report ID.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
000
Detects browsers starting with the remote debugging flags. Which is a technique often used to perform browser injection attacks
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
000
Detects the enabling of the "EnablePeriodicBackup" registry value. Once enabled, The OS will backup System registry hives on restarts to the "C:\Windows\System32\config\RegBack" folder. Windows creates a "RegIdleBackup" task to manage subsequent backups.
Registry backup was a default behavior on Windows and was disabled as of "Windows 10, version 1803".
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
000
The following analytic identifies the creation of new email forwarding rules in an Office 365 environment. It detects events logged under New-InboxRule and Set-InboxRule operations within the o365_management_activity data source, focusing on parameters like ForwardTo, ForwardAsAttachmentTo, and RedirectTo. This activity is significant as unauthorized email forwarding can lead to data exfiltration and unauthorized access to sensitive information. If confirmed malicious, attackers could intercept and redirect emails, potentially compromising confidential communications and leading to data breaches.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0086
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
1 year ago
1081
This analytic identifies the creation of new open/public GCP Storage buckets. It leverages GCP PubSub events, specifically monitoring for the `storage.setIamPermissions` method and checks if the `allUsers` member is added. This activity is significant because open storage buckets can expose sensitive data to the public, posing a severe security risk. If confirmed malicious, an attacker could access, modify, or delete data within the bucket, leading to data breaches and potential compliance violations.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2076
The following analytic identifies access to GCP Storage buckets from new or previously unseen remote IP addresses. It leverages GCP Storage bucket-access logs ingested via Cloud Pub/Sub and compares current access events against a lookup table of previously seen IP addresses. This activity is significant as it may indicate unauthorized access or potential reconnaissance by an attacker. If confirmed malicious, this could lead to data exfiltration, unauthorized data manipulation, or further compromise of the GCP environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0075
This analytic identifies when an O365 email account sends an email and then hard deletes email within a short period (within 1 hour). This behavior may indicate a compromised account where the threat actor is attempting to remove forensic artifacts or evidence of activity. Threat actors often use this technique to prevent defenders and victims from knowing the account has been compromised.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0062
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 analytic detects when emails are accessed in Office 365 Exchange via Exchange Web Services (EWS) using OAuth-authenticated applications. It leverages the ClientInfoString field to identify EWS interactions and aggregates metrics such as access counts, timing, and client IP addresses, categorized by user, ClientAppId, OperationCount, and AppId. Monitoring OAuth applications accessing emails through EWS is crucial for identifying potential abuse or unauthorized data access. If confirmed malicious, this activity could lead to unauthorized email access, data exfiltration, or further compromise of sensitive information.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0061
This analytic identifies when Office 365 users search for suspicious keywords or have an excessive number of queries to a SharePoint site within a limited timeframe. This behavior may indicate that a malicious actor has gained control of a user account and is conducting discovery or enumeration activities.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1061
This analytic identifies an AWS IAM account with concurrent sessions originating from more than one unique IP address within a 5-minute span. This detection leverages AWS CloudTrail logs, specifically the `DescribeEventAggregates` API call, to identify multiple IP addresses associated with the same user session. This behavior is significant as it may indicate a session hijacking attack, where an adversary uses stolen session cookies to access AWS resources from a different location. If confirmed malicious, this activity could allow unauthorized access to sensitive corporate resources, leading to potential data breaches or further exploitation.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2059
The following analytic identifies instances where email forwarding has been enabled on mailboxes within an Office 365 environment. It detects this activity by monitoring the Set-Mailbox operation within the o365_management_activity logs, specifically looking for changes to the ForwardingAddress or ForwardingSmtpAddress parameters. This activity is significant as unauthorized email forwarding can lead to data exfiltration and unauthorized access to sensitive information. If confirmed malicious, attackers could intercept and redirect emails, potentially compromising confidential communications and leading to data breaches.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0059
The following analytic detects the usage of headless browsers within an organization. It identifies processes containing the "--headless" and "--disable-gpu" command line arguments, which are indicative of headless browsing. This detection leverages data from the Endpoint.Processes datamodel to identify such processes. Monitoring headless browser usage is significant as these tools can be exploited by adversaries for malicious activities like web scraping, automated testing, and undetected web interactions. If confirmed malicious, this activity could lead to unauthorized data extraction, automated attacks, or other covert operations on web applications.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
3058
The following analytic identifies when Office 365 users search for suspicious keywords or have an excessive number of queries to a mailbox within a limited timeframe. This behavior may indicate that a malicious actor has gained control of a mailbox and is conducting discovery or enumeration activities.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0057
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