Inter-Process Communication: Dynamic Data Exchange
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 Despite being superseded by Component Object Model, DDE may be enabled in Windows 10 and most of Microsoft Office 2016 via Registry keys.   
Microsoft Office documents can be poisoned with DDE commands  , directly or through embedded files , and used to deliver execution via Phishing campaigns or hosted Web content, avoiding the use of Visual Basic for Applications (VBA) macros.  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.
|M1048||Application Isolation and Sandboxing||
Ensure Protected View is enabled.
|M1040||Behavior Prevention on Endpoint|
|M1042||Disable or Remove Feature or Program||
Registry keys specific to Microsoft Office feature control security can be set to disable automatic DDE/OLE execution.  Microsoft also created, and enabled by default, Registry keys to completely disable DDE execution in Word and Excel.
Monitor processes for abnormal behavior indicative of DDE abuse, such as Microsoft Office applications loading DLLs and other modules not typically associated with the application or these applications spawning unusual processes (such as cmd.exe).
OLE and Office Open XML files can be scanned for ‘DDEAUTO', ‘DDE’, and other strings indicative of DDE execution.
- Cimpanu, C. (2017, December 15). Microsoft Disables DDE Feature in Word to Prevent Further Malware Attacks. Retrieved December 19, 2017.
- Microsoft. (2017, December 12). ADV170021 - Microsoft Office Defense in Depth Update. Retrieved February 3, 2018.
- Microsoft. (2017, November 8). Microsoft Security Advisory 4053440 - Securely opening Microsoft Office documents that contain Dynamic Data Exchange (DDE) fields. Retrieved November 21, 2017.
- El-Sherei, S. (2016, May 20). PowerShell, C-Sharp and DDE The Power Within. Retrieved November 22, 2017.
- Kettle, J. (2014, August 29). Comma Separated Vulnerabilities. Retrieved November 22, 2017.
- Nelson, M. (2018, January 29). Reviving DDE: Using OneNote and Excel for Code Execution. Retrieved February 3, 2018.
- Stalmans, E., El-Sherei, S. (2017, October 9). Macro-less Code Exec in MSWord. Retrieved November 21, 2017.
- Sherstobitoff, R., Rea, M. (2017, November 7). Threat Group APT28 Slips Office Malware into Doc Citing NYC Terror Attack. Retrieved November 21, 2017.
- Paganini, P. (2017, November 9). Russia-Linked APT28 group observed using DDE attack to deliver malware. Retrieved November 21, 2017.
- Lee, B., Falcone, R. (2018, June 06). Sofacy Group’s Parallel Attacks. Retrieved June 18, 2018.
- Raiu, C., and Ivanov, A. (2016, June 17). Operation Daybreak. Retrieved February 15, 2018.
- Svajcer, V. (2018, July 31). Multiple Cobalt Personality Disorder. Retrieved September 5, 2018.
- Waterman, S. (2017, October 16). Fin7 weaponization of DDE is just their latest slick move, say researchers. Retrieved November 21, 2017.
- Symantec Security Response. (2018, October 10). Gallmaker: New Attack Group Eschews Malware to Live off the Land. Retrieved November 27, 2018.
- Mercer, W., Rascagneres, P. (2018, April 26). GravityRAT - The Two-Year Evolution Of An APT Targeting India. Retrieved May 16, 2018.
- Patil, S. and Williams, M.. (2019, June 5). Government Sector in Central Asia Targeted With New HAWKBALL Backdoor Delivered via Microsoft Office Vulnerabilities. Retrieved June 20, 2019.
- Parys, B. (2017, February 11). The KeyBoys are back in town. Retrieved June 13, 2019.
- Kaspersky Lab's Global Research & Analysis Team. (2018, October 10). MuddyWater expands operations. Retrieved November 2, 2018.
- Lunghi, D., et al. (2017, December). Untangling the Patchwork Cyberespionage Group. Retrieved July 10, 2018.
- Mercer, W, et al. (2020, April 16). PoetRAT: Python RAT uses COVID-19 lures to target Azerbaijan public and private sectors. Retrieved April 27, 2020.
- Singh, S. et al.. (2018, March 13). Iranian Threat Group Updates Tactics, Techniques and Procedures in Spear Phishing Campaign. Retrieved April 11, 2018.
- Sanmillan, I.. (2020, May 13). Ramsay: A cyber‑espionage toolkit tailored for air‑gapped networks. Retrieved May 27, 2020.
- Faou, M. and Boutin, J. (2017, February). Read The Manual: A Guide to the RTM Banking Trojan. Retrieved March 9, 2017.
- Sherstobitoff, R., Malhotra, A., et. al.. (2018, December 18). Operation Sharpshooter Campaign Targets Global Defense, Critical Infrastructure. Retrieved May 14, 2020.
- Rewertz. (2020, April 20). Sidewinder APT Group Campaign Analysis. Retrieved January 29, 2021.
- Rewterz. (2020, June 22). Analysis on Sidewinder APT Group – COVID-19. Retrieved January 29, 2021.
- Proofpoint Staff. (2018, June 8). TA505 shifts with the times. Retrieved May 28, 2019.
- Reaves, J. and Platt, J. (2020, June). Valak Malware and the Connection to Gozi Loader ConfCrew. Retrieved August 31, 2020.
- Microsoft. (n.d.). What is Protected View?. Retrieved November 22, 2017.
- Brower, N. & D'Souza-Wiltshire, I. (2017, November 9). Enable Attack surface reduction. Retrieved February 3, 2018.
- Dormann, W. (2017, October 20). Disable DDEAUTO for Outlook, Word, OneNote, and Excel versions 2010, 2013, 2016. Retrieved February 3, 2018.
- NVISO Labs. (2017, October 11). Detecting DDE in MS Office documents. Retrieved November 21, 2017.