Detections

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

8,410 detections

Detects the injection of code by overwriting the memory map of a Linux process using the "dd" Linux command. This technique leverages the /proc filesystem to modify a running process's memory, which can be used for privilege escalation or defense evasion.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
3133
This rule detects attempts to enable the guest account on macOS systems using the `sysadminctl` utility. Adversaries may enable the guest account to establish persistence, evade defenses, or gain initial access by leveraging a default, often less monitored, account.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
1033
This rule detects the creation or registration of scheduled tasks using PowerShell cmdlets or WMI methods. It specifically looks for the use of `New-ScheduledTaskAction`, `New-ScheduledTaskTrigger`, `New-ScheduledTaskPrincipal`, `New-ScheduledTaskSettingsSet`, `New-ScheduledTask`, `Register-ScheduledTask` cmdlets, or the `Invoke-CimMethod` cmdlet targeting the `PS_ScheduledTask` class within the `Root\Microsoft\Windows\TaskScheduler` namespace. This activity is often abused by adversaries for persistence, privilege escalation, and execution.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0033
Detects activity when an AWS user's login profile (password) is modified by another user. This can indicate an attacker with the "iam:UpdateLoginProfile" permission is changing passwords on behalf of other users to gain access to the AWS console.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0032
This rule detects when a user is removed from a group that has Conditional Access (CA) policy modification access within Azure Active Directory. Such groups are critical for managing access to resources, and unauthorized removal of members could indicate an attempt to evade detection, disrupt security controls, or prepare for further malicious activity. Monitoring these removals helps identify potential privilege escalation, defense evasion, or persistence attempts.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0032
This rule detects a measurable increase of successful authentications, specifically when the count of successful sign-ins increases by 10% or greater. This could indicate an adversary attempting to gain access through brute-force, password spraying, or credential stuffing attacks, or potentially an increase in legitimate user activity that needs to be baselined.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0032
Detects attempts to discover files with setuid/setgid capabilities using the 'getcap' command. This activity is often a precursor to privilege escalation on Linux systems, as adversaries search for binaries that can be abused to gain higher privileges.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0032
This rule detects the creation of new files within the `/etc/sudoers.d/` directory. Files in this directory can be used to grant specific users or groups elevated privileges without requiring a password, serving as a persistence mechanism for attackers to maintain privileged access.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
1132
This rule detects attempts to add a user to the 'admin' group on macOS systems using the `dscl` command-line utility. Specifically, it looks for `dscl` commands that include the `-append` option, target the `/Groups/admin` path, and modify `GroupMembership`. This activity is often associated with privilege escalation or persistence by granting administrative rights to a standard user account.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
2032
This rule detects suspicious DCE-RPC function calls that indicate remote execution techniques on a Windows system. It specifically looks for operations related to scheduled tasks (JobAdd, SchRpcEnableTask, SchRpcRegisterTask, SchRpcRun), WMI execution (ExecMethod, ExecMethodAsync), and service creation/start (CreateServiceA/W, StartServiceA/W). These activities are commonly abused by adversaries for initial access, persistence, and lateral movement.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0032
Detects successful logon from public IP address via SMB. This can indicate a publicly-exposed SMB port.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
2032
Detects a failed logon attempt from a public IP address on a Windows system. This can indicate an attempt to gain unauthorized access, potentially through brute-force attacks or credential stuffing, especially if the system is not intended to be exposed to the internet for direct login.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
2032
This rule detects attempts to backdoor a domain object by granting DCSync rights to a regular user or machine account. This is achieved by modifying the 'ntSecurityDescriptor' attribute in Active Directory, specifically looking for GUIDs associated with DCSync extended rights. Such a modification allows the designated account to perform DCSync attacks, enabling the retrieval of password hashes for any user or computer in the domain.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
3032
Detects unusual processes accessing 'desktop.ini' remotely over a network share with write permissions. This activity can be leveraged to alter how Windows Explorer displays a folder's content (e.g., renaming files) without actually changing the files on disk, which can be used for persistence or privilege escalation.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
1032
Detects the creation or modification of a computer account or user account with a suspicious name pattern 'SAMTHEADMIN-X$' (where X is a number) which is known to be generated by a hacktool exploiting CVE-2021-42287 and CVE-2021-42278. This pattern is associated with the 'Sam the Admin' vulnerability exploitation.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
1032
This rule detects the addition of a new conditional access policy within an Azure environment. Conditional Access policies are critical security controls that determine when and how users can access resources. Unauthorized or unexpected changes to these policies could indicate an attacker attempting to establish persistence, bypass existing security controls (like MFA), or gain unauthorized access by modifying access conditions.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0031
Detects the use of 'at' or 'atd' utilities, which are commonly abused by adversaries for persistence or to schedule the execution of malicious code. This rule specifically looks for the execution of '/at' or '/atd' binaries.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0031
This rule detects suspicious sign-in activities that occur shortly after a network connection to an IP address associated with 'Lab539 Clickfix'. It correlates risky sign-in events from Azure Active Directory (AAD) with network connection logs from devices. Specifically, it looks for AAD sign-ins with a risk level of 30 or higher, from non-guest, non-compliant, and non-managed devices, where the IP address has not been seen for that user in the last 30 days. This is then joined with network connection events to IP addresses found in the 'Lab539 Clickfix' external data, ensuring the sign-in occurs after the network connection within a short timeframe. The 'Lab539 Clickfix' reference suggests a connection to a known threat or campaign, possibly related to phishing or credential compromise.
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Benjamin Zulliger@benscha
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Detections.ai Community
1 year ago
244715
This rule detects the creation of AWS API keys for a user by a different user. This activity is indicative of a backdoored user account being used to establish persistence within an AWS environment. It can also help identify unusual flows of AWS key creation within an organization.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0030
This rule detects anomalous user activity patterns, specifically focusing on suspicious changes to directories or other behaviors that Microsoft Entra ID Protection identifies as 'anomalousUserActivity'. This could indicate compromised accounts or insider threats.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0030
Detects when a Google Workspace user is granted administrative privileges. This could indicate a legitimate administrative action or a malicious attempt to escalate privileges within the Google Workspace environment.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0030
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