EXPLORE DETECTIONS
Windows RDP Bitmap Cache File Creation
This detection identifies the creation of Remote Desktop Protocol (RDP) bitmap cache files on a Windows system, typically located in the user’s profile under the Terminal Server Client cache directory. These files (*.bmc, cache*.bin) are generated when a user initiates an RDP session using the built-in mstsc.exe client. Their presence can indicate interactive remote access activity and may be useful in detecting lateral movement or unauthorized RDP usage. Monitoring this behavior is especially important, as attackers may attempt to delete or suppress these artifacts to evade forensic analysis.
Windows RDP Cache File Deletion
This detection identifies the deletion of RDP bitmap cache files—specifically .bmc and .bin files—typically stored in the user profile under the Terminal Server Client\Cache directory. These files are created by the native Windows Remote Desktop Client (mstsc.exe) and store graphical elements from remote sessions to improve performance. Deleting these files may indicate an attempt to remove forensic evidence of RDP usage. While rare in legitimate user behavior, this action is commonly associated with defense evasion techniques used by attackers or red teamers who wish to hide traces of interactive remote access. When observed in conjunction with recent logon activity, RDP session indicators, or script execution, this behavior should be treated as potentially malicious. Monitoring for deletion of these files provides valuable visibility into anti-forensic actions that often follow lateral movement or hands-on-keyboard activity.
Windows RDP Client Launched with Admin Session
This detection identifies the execution of the Windows Remote Desktop Client (mstsc.exe) with the "/v" and /admin command-line arguments. The "/v" flag specifies the remote host to connect to, while the /admin flag initiates a connection to the target system’s console session, often used for administrative purposes. This combination may indicate that a user or attacker is performing privileged remote access, potentially to manage a system without disrupting existing user sessions. While such usage may be legitimate for IT administrators, it is less common in typical user behavior. Threat actors may abuse this capability during lateral movement to maintain stealthy access to high-value systems. Monitoring for this pattern can help detect interactive hands-on-keyboard activity, privilege abuse, or attempts to access critical infrastructure without leaving typical login traces associated with non-admin RDP sessions.
Windows RDP Connection Successful
The following analytic detects successful Remote Desktop Protocol (RDP) connections by monitoring EventCode 1149 from the Windows TerminalServices RemoteConnectionManager Operational log. This detection is significant as successful RDP connections can indicate remote access to a system, which may be leveraged by attackers to control or exfiltrate data. If confirmed malicious, this activity could lead to unauthorized access, data theft, or further lateral movement within the network. Monitoring successful RDP connections is crucial for identifying potential security breaches and mitigating risks promptly.
Windows RDP File Execution
The following analytic detects when a Windows RDP client attempts to execute an RDP file from a temporary directory, downloads directory, or Outlook directories. This detection is significant as it can indicate an attempt for an adversary to deliver a .rdp file, which may be leveraged by attackers to control or exfiltrate data. If confirmed malicious, this activity could lead to unauthorized access, data theft, or further lateral movement within the network.
Windows RDP Login Session Was Established
The following analytic detects instances where a successful Remote Desktop Protocol (RDP) login session was established, as indicated by Windows Security Event ID 4624 with Logon Type 10. This event confirms that a user has not only provided valid credentials but has also initiated a full interactive RDP session. It is a key indicator of successful remote access to a Windows system. When correlated with Event ID 1149, which logs RDP authentication success, this analytic helps distinguish between mere credential acceptance and actual session establishment—critical for effective monitoring and threat detection.
Windows RDP Server Registry Deletion
This detection identifies the deletion of registry keys under HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client\Servers\, which store records of previously connected remote systems via Remote Desktop Protocol (RDP). These keys are created automatically when a user connects to a remote host using the native Windows RDP client (mstsc.exe) and can be valuable forensic artifacts for tracking remote access activity. Malicious actors aware of this behavior may delete these keys after using RDP to hide evidence of their activity and avoid detection during incident response. This form of artifact cleanup is a known defense evasion technique, often performed during or after lateral movement. Legitimate users rarely delete these keys manually, making such actions highly suspicious—especially when correlated with RDP usage, unusual logon behavior, or other signs of compromise. Detecting the deletion of these registry entries can provide crucial insight into attempts to cover tracks following interactive remote access.
Windows RDP Server Registry Entry Created
This detection identifies the creation of registry keys under HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client\Servers\, which occur when a user initiates a Remote Desktop Protocol (RDP) connection using the built-in Windows RDP client (mstsc.exe). These registry entries store information about previously connected remote hosts, including usernames and display settings. Their creation is a strong indicator that an outbound RDP session was initiated from the system. While the presence of these keys is normal during legitimate RDP use, their appearance can be used to track remote access activity, especially in environments where RDP is tightly controlled. In post-compromise scenarios, these artifacts may be created by threat actors using RDP for lateral movement or command-and-control. Monitoring the creation of these registry entries can help defenders detect initial use of RDP from a compromised host, particularly when correlated with unusual user behavior, logon patterns, or network activity.
Windows RDPClient Connection Sequence Events
This analytic monitors Windows RDP client connection sequence events (EventCode 1024) from the Microsoft-Windows-TerminalServices-RDPClient/Operational log. These events track when RDP ClientActiveX initiates connection attempts to remote servers. The connection sequence is a critical phase of RDP where the client and server exchange settings and establish common parameters for the session. Monitoring these events can help identify unusual RDP connection patterns, potential lateral movement attempts, unauthorized remote access activity, and RDP connection chains that may indicate compromised systems. NOTE the analytic was written for Multi-Line as XML was not properly parsed out.
Windows Registry BootExecute Modification
The following analytic detects modifications to the BootExecute registry key, which manages applications and services executed during system boot. It leverages data from the Endpoint.Registry data model, focusing on changes to the registry path "HKLM\\System\\CurrentControlSet\\Control\\Session Manager\\BootExecute". This activity is significant because unauthorized changes to this key can indicate attempts to achieve persistence, load malicious code, or tamper with the boot process. If confirmed malicious, this could allow an attacker to maintain persistence, execute arbitrary code at boot, or disrupt system operations.
Windows Registry Certificate Added
The following analytic detects the installation of a root CA certificate by monitoring specific registry paths for SetValue events. It leverages data from the Endpoint datamodel, focusing on registry paths containing "certificates" and registry values named "Blob." This activity is significant because unauthorized root CA certificates can compromise the integrity of encrypted communications and facilitate man-in-the-middle attacks. If confirmed malicious, this could allow an attacker to intercept, decrypt, or manipulate sensitive data, leading to severe security breaches.
Windows Registry Delete Task SD
The following analytic detects a process attempting to delete a scheduled task's Security Descriptor (SD) from the registry path of that task. It leverages the Endpoint.Registry data model to identify registry actions performed by the SYSTEM user, specifically targeting deletions of the SD value. This activity is significant as it may indicate an attempt to remove evidence of a scheduled task for defense evasion. If confirmed malicious, it suggests an attacker with privileged access trying to hide their tracks, potentially compromising system integrity and security.
Windows Registry Dotnet ETW Disabled Via ENV Variable
The following analytic detects a registry modification that disables the ETW for the .NET Framework. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the COMPlus_ETWEnabled registry value under the "Environment" registry key path for both user (HKCU\Environment) and machine (HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment) scopes. This activity is significant because disabling ETW can allow attackers to evade Endpoint Detection and Response (EDR) tools and hide their execution from audit logs. If confirmed malicious, this action could enable attackers to operate undetected, potentially leading to further compromise and persistent access within the environment.
Windows Registry Entries Exported Via Reg
The following analytic detects the execution of the reg.exe process with either the "save" or "export" parameters. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs and command-line arguments. This activity is significant because threat actors often use the "reg save" or "reg export" command to dump credentials or test registry modification capabilities on compromised hosts. If confirmed malicious, this behavior could allow attackers to escalate privileges, persist in the environment, or access sensitive information stored in the registry.
Windows Registry Entries Restored Via Reg
The following analytic detects the execution of reg.exe with the "restore" parameter, indicating an attempt to restore registry backup data on a host. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs and command-line arguments. This activity is significant as it may indicate post-exploitation actions, such as those performed by tools like winpeas, which use "reg save" and "reg restore" to manipulate registry settings. If confirmed malicious, this could allow an attacker to revert registry changes, potentially bypassing security controls and maintaining persistence.
Windows Registry Modification for Safe Mode Persistence
The following analytic identifies modifications to the SafeBoot registry keys, specifically within the Minimal and Network paths. This detection leverages registry activity logs from endpoint data sources like Sysmon or EDR tools. Monitoring these keys is crucial as adversaries can use them to persist drivers or services in Safe Mode, with Network allowing network connections. If confirmed malicious, this activity could enable attackers to maintain persistence even in Safe Mode, potentially bypassing certain security measures and facilitating further malicious actions.
Windows Registry Payload Injection
The following analytic detects suspiciously long data written to the Windows registry, a behavior often linked to fileless malware or persistence techniques. It leverages Endpoint Detection and Response (EDR) telemetry, focusing on registry events with data lengths exceeding 512 characters. This activity is significant as it can indicate an attempt to evade traditional file-based defenses, making it crucial for SOC monitoring. If confirmed malicious, this technique could allow attackers to maintain persistence, execute code, or manipulate system configurations without leaving a conventional file footprint.
Windows Registry SIP Provider Modification
The following analytic detects modifications to the Windows Registry SIP Provider. It leverages Sysmon EventID 7 to monitor registry changes in paths and values related to Cryptography Providers and OID Encoding Types. This activity is significant as it may indicate an attempt to subvert trust controls, a common tactic for bypassing security measures and maintaining persistence. If confirmed malicious, an attacker could manipulate the system's cryptographic functions, potentially leading to unauthorized access, data theft, or other damaging outcomes. Review the modified registry paths and concurrent processes to identify the attack source.
Windows Regsvr32 Renamed Binary
The following analytic identifies instances where the regsvr32.exe binary has been renamed and executed. This detection leverages Endpoint Detection and Response (EDR) data, specifically focusing on the original filename metadata. Renaming regsvr32.exe is significant as it can be an evasion technique used by attackers to bypass security controls. If confirmed malicious, this activity could allow an attacker to execute arbitrary DLLs, potentially leading to code execution, privilege escalation, or persistence within the environment.
Windows Remote Access Software BRC4 Loaded Dll
The following analytic identifies the loading of four specific Windows DLLs (credui.dll, dbghelp.dll, samcli.dll, winhttp.dll) by a non-standard process. This detection leverages Sysmon EventCode 7 to monitor DLL load events and flags when all four DLLs are loaded within a short time frame. This activity is significant as it may indicate the presence of Brute Ratel C4, a sophisticated remote access tool used for credential dumping and other malicious activities. If confirmed malicious, this behavior could lead to unauthorized access, credential theft, and further compromise of the affected system.
Windows Remote Access Software RMS Registry
The following analytic detects the creation or modification of Windows registry entries related to the Remote Manipulator System (RMS) Remote Admin tool. It leverages data from the Endpoint.Registry datamodel, focusing on registry paths containing "SYSTEM\\Remote Manipulator System." This activity is significant because RMS, while legitimate, is often abused by adversaries, such as in the Azorult malware campaigns, to gain unauthorized remote access. If confirmed malicious, this could allow attackers to remotely control the targeted host, leading to potential data exfiltration, system manipulation, or further network compromise.
Windows Remote Assistance Spawning Process
The following analytic detects Microsoft Remote Assistance (msra.exe) spawning PowerShell.exe or cmd.exe as a child process. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process creation events where msra.exe is the parent process. This activity is significant because msra.exe typically does not spawn command-line interfaces, indicating potential process injection or misuse. If confirmed malicious, an attacker could use this technique to execute arbitrary commands, escalate privileges, or maintain persistence on the compromised system.
Windows Remote Create Service
The following analytic identifies the creation of a new service on a remote endpoint using sc.exe. It leverages data from Endpoint Detection and Response (EDR) agents, specifically monitoring for EventCode 7045, which indicates a new service creation. This activity is significant as it may indicate lateral movement or remote code execution attempts by an attacker. If confirmed malicious, this could allow the attacker to establish persistence, escalate privileges, or execute arbitrary code on the remote system, potentially leading to further compromise of the network.
Windows Remote Desktop Network Bruteforce Attempt
The following analytic identifies potential Remote Desktop Protocol (RDP) brute force attacks by monitoring network traffic for RDP application activity. This query detects potential RDP brute force attacks by identifying source IPs that have made more than 10 connection attempts to the same RDP port on a host within a one-hour window. The results are presented in a table that includes the source and destination IPs, destination port, number of attempts, and the times of the first and last connection attempts, helping to prioritize IPs based on the intensity of activity.