Event 5712: A Remote Procedure Call (RPC) was attempted.

Adversaries may use [Valid Accounts](https://attack.mitre.org/techniques/T1078) to log into a service that accepts remote connections, such as telnet, SSH, and VNC. The adversary may then perform actions as the logged-on user. In an enterprise environment, servers and workstations can be organized into domains. Domains provide centralized identity management, allowing users to login using one set of credentials across the entire network. If an adversary is able to obtain a set of valid domain credentials, they could login to many different machines using remote access protocols such as secure shell (SSH) or remote desktop protocol (RDP).(Citation: SSH Secure Shell)(Citation: TechNet Remote Desktop Services) They could also login to accessible SaaS or IaaS services, such as those that federate their identities to the domain. Legitimate applications (such as [Software Deployment Tools](https://attack.mitre.org/techniques/T1072) and other administrative programs) may utilize [Remote Services](https://attack.mitre.org/techniques/T1021) to access remote hosts. For example, Apple Remote Desktop (ARD) on macOS is native software used for remote management. ARD leverages a blend of protocols, including [VNC](https://attack.mitre.org/techniques/T1021/005) to send the screen and control buffers and [SSH](https://attack.mitre.org/techniques/T1021/004) for secure file transfer.(Citation: Remote Management MDM macOS)(Citation: Kickstart Apple Remote Desktop commands)(Citation: Apple Remote Desktop Admin Guide 3.3) Adversaries can abuse applications such as ARD to gain remote code execution and perform lateral movement. In versions of macOS prior to 10.14, an adversary can escalate an SSH session to an ARD session which enables an adversary to accept TCC (Transparency, Consent, and Control) prompts without user interaction and gain access to data.(Citation: FireEye 2019 Apple Remote Desktop)(Citation: Lockboxx ARD 2019)(Citation: Kickstart Apple Remote Desktop commands)

Adversaries may use [Valid Accounts](https://attack.mitre.org/techniques/T1078) to interact with a remote network share using Server Message Block (SMB). The adversary may then perform actions as the logged-on user. SMB is a file, printer, and serial port sharing protocol for Windows machines on the same network or domain. Adversaries may use SMB to interact with file shares, allowing them to move laterally throughout a network. Linux and macOS implementations of SMB typically use Samba. Windows systems have hidden network shares that are accessible only to administrators and provide the ability for remote file copy and other administrative functions. Example network shares include `C$`, `ADMIN$`, and `IPC$`. Adversaries may use this technique in conjunction with administrator-level [Valid Accounts](https://attack.mitre.org/techniques/T1078) to remotely access a networked system over SMB,(Citation: Wikipedia Server Message Block) to interact with systems using remote procedure calls (RPCs),(Citation: TechNet RPC) transfer files, and run transferred binaries through remote Execution. Example execution techniques that rely on authenticated sessions over SMB/RPC are [Scheduled Task/Job](https://attack.mitre.org/techniques/T1053), [Service Execution](https://attack.mitre.org/techniques/T1569/002), and [Windows Management Instrumentation](https://attack.mitre.org/techniques/T1047). Adversaries can also use NTLM hashes to access administrator shares on systems with [Pass the Hash](https://attack.mitre.org/techniques/T1550/002) and certain configuration and patch levels.(Citation: Microsoft Admin Shares)

Adversaries may use [Valid Accounts](https://attack.mitre.org/techniques/T1078) to interact with remote machines by taking advantage of Distributed Component Object Model (DCOM). The adversary may then perform actions as the logged-on user. The Windows Component Object Model (COM) is a component of the native Windows application programming interface (API) that enables interaction between software objects, or executable code that implements one or more interfaces. Through COM, a client object can call methods of server objects, which are typically Dynamic Link Libraries (DLL) or executables (EXE). Distributed COM (DCOM) is transparent middleware that extends the functionality of COM beyond a local computer using remote procedure call (RPC) technology.(Citation: Fireeye Hunting COM June 2019)(Citation: Microsoft COM) Permissions to interact with local and remote server COM objects are specified by access control lists (ACL) in the Registry.(Citation: Microsoft Process Wide Com Keys) By default, only Administrators may remotely activate and launch COM objects through DCOM.(Citation: Microsoft COM ACL) Through DCOM, adversaries operating in the context of an appropriately privileged user can remotely obtain arbitrary and even direct shellcode execution through Office applications(Citation: Enigma Outlook DCOM Lateral Movement Nov 2017) as well as other Windows objects that contain insecure methods.(Citation: Enigma MMC20 COM Jan 2017)(Citation: Enigma DCOM Lateral Movement Jan 2017) DCOM can also execute macros in existing documents(Citation: Enigma Excel DCOM Sept 2017) and may also invoke [Dynamic Data Exchange](https://attack.mitre.org/techniques/T1559/002) (DDE) execution directly through a COM created instance of a Microsoft Office application(Citation: Cyberreason DCOM DDE Lateral Movement Nov 2017), bypassing the need for a malicious document. DCOM can be used as a method of remotely interacting with [Windows Management Instrumentation](https://attack.mitre.org/techniques/T1047). (Citation: MSDN WMI)

Adversaries may use [Valid Accounts](https://attack.mitre.org/techniques/T1078) to interact with remote systems using Windows Remote Management (WinRM). The adversary may then perform actions as the logged-on user. WinRM is the name of both a Windows service and a protocol that allows a user to interact with a remote system (e.g., run an executable, modify the Registry, modify services).(Citation: Microsoft WinRM) It may be called with the `winrm` command or by any number of programs such as PowerShell.(Citation: Jacobsen 2014) WinRM can be used as a method of remotely interacting with [Windows Management Instrumentation](https://attack.mitre.org/techniques/T1047).(Citation: MSDN WMI)