EXPLORE DETECTIONS
Windows Multiple Account Passwords Changed
The following analytic detects instances where more than five unique Windows account passwords are changed within a 10-minute interval. It leverages Event Code 4724 from the Windows Security Event Log, using the wineventlog_security dataset to monitor and count distinct TargetUserName values. This behavior is significant as rapid password changes across multiple accounts are unusual and may indicate unauthorized access or internal compromise. If confirmed malicious, this activity could lead to widespread account compromise, unauthorized access to sensitive information, and potential disruption of services.
Windows Multiple Accounts Deleted
The following analytic detects the deletion of more than five unique Windows accounts within a 10-minute period, using Event Code 4726 from the Windows Security Event Log. It leverages the `wineventlog_security` dataset, segmenting data into 10-minute intervals to identify suspicious account deletions. This activity is significant as it may indicate an attacker attempting to erase traces of their actions. If confirmed malicious, this could lead to unauthorized access removal, hindering incident response and forensic investigations.
Windows Multiple Accounts Disabled
The following analytic identifies instances where more than five unique Windows accounts are disabled within a 10-minute window, as indicated by Event Code 4725 in the Windows Security Event Log. It leverages the wineventlog_security dataset, grouping data into 10-minute segments and tracking the count and distinct count of TargetUserName. This behavior is significant as it may indicate internal policy breaches or an external attacker's attempt to disrupt operations. If confirmed malicious, this activity could lead to widespread account lockouts, hindering user access and potentially disrupting business operations.
Windows Multiple Disabled Users Failed To Authenticate Wth Kerberos
The following analytic detects a single source endpoint failing to authenticate with 30 unique disabled domain users using the Kerberos protocol within 5 minutes. It leverages Windows Security Event 4768, focusing on failure code `0x12`, indicating revoked credentials. This activity is significant as it may indicate a Password Spraying attack targeting disabled accounts, a tactic used by adversaries to gain initial access or elevate privileges. If confirmed malicious, this could lead to unauthorized access or privilege escalation within the Active Directory environment, posing a severe security risk.
Windows Multiple Invalid Users Fail To Authenticate Using Kerberos
The following analytic identifies a source endpoint failing to authenticate with 30 unique invalid domain users using the Kerberos protocol. This detection leverages EventCode 4768, specifically looking for failure code 0x6, indicating the user is not found in the Kerberos database. This activity 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 could lead to unauthorized access or privilege escalation within the Active Directory environment, posing a significant security risk.
Windows Multiple Invalid Users Failed To Authenticate Using NTLM
The following analytic detects a single source endpoint failing to authenticate with 30 unique invalid users using the NTLM protocol. It leverages EventCode 4776 from Domain Controller logs, focusing on error code 0xC0000064, which indicates non-existent usernames. 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, and potential compromise of sensitive information within the Active Directory environment.
Windows Multiple NTLM Null Domain Authentications
The following analytic detects when a device is the target of numerous NTLM authentications using a null domain. This activity generally results when an attacker attempts to brute force, password spray, or otherwise authenticate to a domain joined Windows device from a non-domain device. This activity may also generate a large number of EventID 4776 events in tandem, however these events will not indicate the attacker or target device
Windows Multiple Users Fail To Authenticate Wth ExplicitCredentials
The following analytic identifies a source user failing to authenticate with 30 unique users using explicit credentials on a host. It leverages Windows Event 4648, which is generated when a process attempts an account logon by explicitly specifying account credentials. This detection is significant as it may indicate a Password Spraying attack, where an adversary attempts to gain initial access or elevate privileges within an Active Directory environment. If confirmed malicious, this activity could lead to unauthorized access, privilege escalation, and potential compromise of sensitive information.
Windows Multiple Users Failed To Authenticate From Host Using NTLM
The following analytic identifies a single source endpoint failing to authenticate with 30 unique valid users using the NTLM protocol. It leverages EventCode 4776 from Domain Controller logs, focusing on error code 0xC000006A, which indicates a bad password. 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 to sensitive information or further compromise of the Active Directory environment.
Windows Multiple Users Failed To Authenticate From Process
The following analytic detects a source process failing to authenticate with 30 unique users, indicating a potential Password Spraying attack. It leverages Windows Event 4625 with Logon Type 2, collected from domain controllers, member servers, and workstations. 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, this could lead to unauthorized access, privilege escalation, or further compromise of the network, posing a severe security risk.
Windows Multiple Users Failed To Authenticate Using Kerberos
The following analytic identifies a single source endpoint failing to authenticate with 30 unique users using the Kerberos protocol. It leverages EventCode 4771 with Status 0x18, indicating wrong password attempts, and aggregates these events over a 5-minute window. This behavior is significant as it may indicate a Password Spraying attack, where an adversary attempts to gain initial access or elevate privileges in an Active Directory environment. If confirmed malicious, this activity could lead to unauthorized access, privilege escalation, and potential compromise of sensitive information.
Windows Multiple Users Remotely Failed To Authenticate From Host
The following analytic identifies a source host failing to authenticate against a remote host with 30 unique users. It leverages Windows Event 4625 with Logon Type 3, indicating remote authentication attempts. This behavior is significant as it may indicate a Password Spraying attack, where an adversary attempts to gain initial access or elevate privileges in an Active Directory environment. If confirmed malicious, this activity could lead to unauthorized access, privilege escalation, and potential compromise of sensitive information. This detection is crucial for real-time security monitoring and threat hunting.
Windows Net System Service Discovery
The following analytic detects the enumeration of Windows services using the net start command, which is a built-in utility that lists all running services on a system. Adversaries, system administrators, or automated tools may use this command to gain situational awareness of what services are active, identify potential security software, or discover opportunities for privilege escalation and lateral movement. The execution of net start is often associated with reconnaissance activity during the early stages of an intrusion, as attackers attempt to map out the system’s defense mechanisms and operational services. By monitoring process execution for instances of cmd.exe /c net start or similar command-line usage, defenders can detect potentially suspicious activity. Correlating this behavior with other reconnaissance commands, such as tasklist or sc query, strengthens detection fidelity. While net start is not inherently malicious, unusual or repeated use in non-administrative contexts should be flagged for further investigation.
Windows NetSupport RMM DLL Loaded By Uncommon Process
The following analytic detects the loading of specific dynamic-link libraries (DLLs) associated with the NetSupport Remote Manager (RMM) tool by any process on a Windows system. Modules such as CryptPak.dll, HTCTL32.DLL, IPCTL32.DLL, keyshowhook.dll, pcicapi.DLL, PCICL32.DLL, and TCCTL32.DLL, are integral to NetSupport's functionality. This detection is particularly valuable when these modules are loaded by processes running from unusual directories (e.g., Downloads, ProgramData, or user-specific folders) rather than the legitimate Program Files installation path, or by executables that have been renamed but retain the internal "client32" identifier. This helps to identify instances where the legitimate NetSupport tool is being misused by adversaries as a Remote Access Trojan (RAT).
Windows Network Connection Discovery Via Net
The following analytic identifies the execution of `net.exe` with command-line arguments used to list or display information about computer connections. 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 network reconnaissance by adversaries or Red Teams, aiming to gather situational awareness and Active Directory information. If confirmed malicious, this behavior could allow attackers to map the network, identify critical assets, and plan further attacks, potentially leading to data exfiltration or lateral movement.
Windows Network Share Interaction Via Net
The following analytic identifies network share discovery and collection activities performed on Windows systems using the Net command. Attackers often use network share discovery to identify accessible shared resources within a network, which can be a precursor to privilege escalation or data exfiltration. By monitoring Windows Event Logs for the usage of the Net command to list and interact with network shares, this detection helps identify potential reconnaissance and collection activities.
Windows New Custom Security Descriptor Set On EventLog Channel
The following analytic detects suspicious modifications to the EventLog security descriptor registry value for defense evasion. It leverages data from the Endpoint.Registry data model, focusing on changes to the "CustomSD" value within the "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Eventlog\<Channel>\CustomSD" path. This activity is significant as changes to the access permissions of the event log could blind security products and help attackers evade defenses. If confirmed malicious, this could allow attackers to block users and security products from viewing, ingesting and interacting event logs.
Windows New Default File Association Value Set
The following analytic detects registry changes to the default file association value. It leverages data from the Endpoint data model, specifically monitoring registry paths under "HKCR\\*\\shell\\open\\command\\*". This activity can be significant because, attackers might alter the default file associations in order to execute arbitrary scripts or payloads when a user opens a file, leading to potential code execution. If confirmed malicious, this technique can enable attackers to persist on the compromised host and execute further malicious commands, posing a severe threat to the environment.
Windows New Deny Permission Set On Service SD Via Sc.EXE
The following analytic detects changes in a service security descriptor where a new deny ace has been added. It leverages data from Endpoint Detection and Response (EDR) agents, specifically searching for any process execution involving the "sc.exe" binary with the "sdset" flag targeting any service and adding a dedicated deny ace to specific groups. If confirmed malicious, this could allow an attacker to escalate their privileges, blind defenses and more. Investigate appropariate services and groups to determine if the behavior is malicious.
Windows New EventLog ChannelAccess Registry Value Set
The following analytic detects suspicious modifications to the EventLog security descriptor registry value for defense evasion. It leverages data from the Endpoint.Registry data model, focusing on changes to the "CustomSD" value within the "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Eventlog\<Channel>\CustomSD" path. This activity is significant as changes to the access permissions of the event log could blind security products and help attackers evade defenses. If confirmed malicious, this could allow attackers to block users and security products from viewing, ingesting and interacting event logs.
Windows New InProcServer32 Added
The following analytic detects the addition of new InProcServer32 registry keys on Windows endpoints. It leverages data from the Endpoint.Registry datamodel to identify changes in registry paths associated with InProcServer32. This activity is significant because malware often uses this mechanism to achieve persistence or execute malicious code by registering a new InProcServer32 key pointing to a harmful DLL. If confirmed malicious, this could allow an attacker to persist in the environment or execute arbitrary code, posing a significant threat to system integrity and security.
Windows New Service Security Descriptor Set Via Sc.EXE
The following analytic detects changes in a service security descriptor. It leverages data from Endpoint Detection and Response (EDR) agents, specifically searching for any process execution involving the "sc.exe" binary with the "sdset" flag targeting any service. This behavior can be legitimate, such as when a user or administrator is configuring a service's security settings. Investigate appropariate services to determine if the behavior is malicious. If confirmed malicious, this could allow an attacker to escalate their privileges, blind defenses and more.
Windows Ngrok Reverse Proxy Usage
The following analytic detects the execution of ngrok.exe on a Windows operating system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line arguments. This activity is significant because while ngrok is a legitimate tool for creating secure tunnels, it is increasingly used by adversaries to bypass network defenses and establish reverse proxies. If confirmed malicious, this could allow attackers to exfiltrate data, maintain persistence, or facilitate further attacks by tunneling traffic through the compromised system.
Windows NirSoft AdvancedRun
The following analytic detects the execution of AdvancedRun.exe, a tool with capabilities similar to remote administration programs like PsExec. It identifies the process by its name or original file name and flags common command-line arguments. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and command-line telemetry. Monitoring this activity is crucial as AdvancedRun can be used for remote code execution and configuration-based automation. If malicious, this could allow attackers to execute arbitrary commands, escalate privileges, or maintain persistence within the environment.