Query: actor TTPs: Inter-Process Communication
Matching passage: T1559 Inter-Process Communication. Tactics: execution. Description: Adversaries may abuse inter-process communication (IPC) mechanisms for local code or command execution. IPC is typically used by processes to share data, communicate with each other, or synchronize execution. IPC is also commonly used to avoid situations such as deadlocks, which occurs when processes are stuck in a cyclic waiting pattern. Adversaries may abuse IPC to execute arbitrary code or commands. IPC mechanisms may differ depending on OS, but typically exists in a form accessible through programming languages/libraries or native interfaces such as Windows [Dynamic Data Exchange](https://attack.mitre.org/techniques/T1559/002) or [Component Object Model](https://attack.mitre.org/techniques/T1559/001). Linux environments support several different IPC mechanisms, two of which being sockets and pipes.(Citation: Linux IPC) Higher level execution mediums, such as those of [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059)s, may also leverage underlying IPC mechanisms. Adversaries may also use [Remote Services](https://attack.mitre.org/techniques/T1021) such as [Distributed Component Object Model](https://attack.mitre.org/techniques/T1021/003) to facilitate remote IPC execution.(Citation: Fireeye Hunting COM June 2019)
Near-miss passage: T1559.002 Dynamic Data Exchange. Tactics: execution. Description: Adversaries may use Windows Dynamic Data Exchange (DDE) to execute arbitrary commands. DDE is a client-server protocol for one-time and/or continuous inter-process communication (IPC) between applications. Once a link is established, applications can autonomously exchange transactions consisting of strings, warm data links (notifications when a data item changes), hot data links (duplications of changes to a data item), and requests for command execution. Object Linking and Embedding (OLE), or the ability to link data between documents, was originally implemented through DDE. Despite being superseded by [Component Object Model](https://attack.mitre.org/techniques/T1559/001), DDE may be enabled in Windows 10 and most of Microsoft Office 2016 via Registry keys.(Citation: BleepingComputer DDE Disabled in Word Dec 2017)(Citation: Microsoft ADV170021 Dec 2017)(Citation: Microsoft DDE Advisory Nov 2017) Microsoft Office documents can be poisoned with DDE commands, directly or through embedded files, and used to deliver execution via [Phishing](https://attack.mitre.org/techniques/T1566) campaigns or hosted Web content, avoiding the use of Visual Basic for Applications (VBA) macros.(Citation: SensePost PS DDE May 2016)(Citation: Kettle CSV DDE Aug 2014)(Citation: Enigma Reviving DDE Jan 2018)(Citation: SensePost MacroLess DDE Oct 2017) Similarly, adversaries may infect payloads to execute applications and/or commands on a victim device by way of embedding DDE formulas within a CSV file intended to be opened through a Windows spreadsheet program.(Citation: OWASP CSV Injection)(Citation: CSV Excel Macro Injection ) DDE could also be leveraged by an adversary operating on a compromised machine who does not have direct access to a [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059). DDE execution can be invoked remotely via [Remote Services](https://attack.mitre.org/techniques/T1021) such as [Distributed Component Object Model](https://attack.mitre.or