Exploitation for Client Execution
Adversaries may exploit software vulnerabilities in client applications to execute code. Vulnerabilities can exist in software due to unsecure coding practices that can lead to unanticipated behavior. Adversaries can take advantage of certain vulnerabilities through targeted exploitation for the purpose of arbitrary code execution. Oftentimes the most valuable exploits to an offensive toolkit are those that can be used to obtain code execution on a remote system because they can be used to gain access to that system. Users will expect to see files related to the applications they commonly used to do work, so they are a useful target for exploit research and development because of their high utility.
Several types exist:
Web browsers are a common target through Drive-by Compromise and Spearphishing Link. Endpoint systems may be compromised through normal web browsing or from certain users being targeted by links in spearphishing emails to adversary controlled sites used to exploit the web browser. These often do not require an action by the user for the exploit to be executed.
Common office and productivity applications such as Microsoft Office are also targeted through Phishing. Malicious files will be transmitted directly as attachments or through links to download them. These require the user to open the document or file for the exploit to run.
Common Third-party Applications
Other applications that are commonly seen or are part of the software deployed in a target network may also be used for exploitation. Applications such as Adobe Reader and Flash, which are common in enterprise environments, have been routinely targeted by adversaries attempting to gain access to systems. Depending on the software and nature of the vulnerability, some may be exploited in the browser or require the user to open a file. For instance, some Flash exploits have been delivered as objects within Microsoft Office documents.
APT12 has exploited multiple vulnerabilities for execution, including Microsoft Office vulnerabilities (CVE-2009-3129, CVE-2012-0158) and vulnerabilities in Adobe Reader and Flash (CVE-2009-4324, CVE-2009-0927, CVE-2011-0609, CVE-2011-0611).
BlackTech has exploited multiple vulnerabilities for execution, including Microsoft Office vulnerabilities CVE-2012-0158, CVE-2014-6352, CVE-2017-0199, and Adobe Flash CVE-2015-5119.
Cobalt Group had exploited multiple vulnerabilities for execution, including Microsoft’s Equation Editor (CVE-2017-11882), an Internet Explorer vulnerability (CVE-2018-8174), CVE-2017-8570, CVE-2017-0199, and CVE-2017-8759.
Patchwork uses malicious documents to deliver remote execution exploits as part of. The group has previously exploited CVE-2017-8570, CVE-2012-1856, CVE-2014-4114, CVE-2017-0199, CVE-2017-11882, and CVE-2015-1641.
SpeakUp attempts to exploit the following vulnerabilities in order to execute its malicious script: CVE-2012-0874, CVE-2010-1871, CVE-2017-10271, CVE-2018-2894, CVE-2016-3088, JBoss AS 3/4/5/6, and the Hadoop YARN ResourceManager. 
|The White Company|
|Application Isolation and Sandboxing||
Other types of virtualization and application microsegmentation may also mitigate the impact of client-side exploitation. Risks of additional exploits and weaknesses in those systems may still exist. 
Security applications that look for behavior used during exploitation such as Windows Defender Exploit Guard (WDEG) and the Enhanced Mitigation Experience Toolkit (EMET) can be used to mitigate some exploitation behavior.  Control flow integrity checking is another way to potentially identify and stop a software exploit from occurring.  Many of these protections depend on the architecture and target application binary for compatibility.
Detecting software exploitation may be difficult depending on the tools available. Also look for behavior on the endpoint system that might indicate successful compromise, such as abnormal behavior of the browser or Office processes. This could include suspicious files written to disk, evidence of Process Injection for attempts to hide execution, evidence of Discovery, or other unusual network traffic that may indicate additional tools transferred to the system.
- Nunez, N. (2017, August 9). Moving Beyond EMET II – Windows Defender Exploit Guard. Retrieved March 12, 2018.
- Wikipedia. (2018, January 11). Control-flow integrity. Retrieved March 12, 2018.
- Cowan, C. (2017, March 23). Strengthening the Microsoft Edge Sandbox. Retrieved March 12, 2018.
- Goodin, D. (2017, March 17). Virtual machine escape fetches $105,000 at Pwn2Own hacking contest - updated. Retrieved March 12, 2018.
- Sherstobitoff, R. (2018, March 08). Hidden Cobra Targets Turkish Financial Sector With New Bankshot Implant. Retrieved May 18, 2018.
- Falcone, R. (2018, March 15). Sofacy Uses DealersChoice to Target European Government Agency. Retrieved June 4, 2018.
- Xiao, C. (2018, September 17). Xbash Combines Botnet, Ransomware, Coinmining in Worm that Targets Linux and Windows. Retrieved November 14, 2018.
- Trend Micro. (2018, September 19). New Multi-Platform Xbash Packs Obfuscation, Ransomware, Coinminer, Worm and Botnet. Retrieved June 4, 2019.
- Check Point Research. (2019, February 4). SpeakUp: A New Undetected Backdoor Linux Trojan. Retrieved April 17, 2019.
- 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.
- Marschalek, M.. (2014, December 16). EvilBunny: Malware Instrumented By Lua. Retrieved June 28, 2019.
- Sanmillan, I.. (2020, May 13). Ramsay: A cyber‑espionage toolkit tailored for air‑gapped networks. Retrieved May 27, 2020.
- Raiu, C., and Ivanov, A. (2016, June 17). Operation Daybreak. Retrieved February 15, 2018.
- FireEye. (2018, February 20). APT37 (Reaper): The Overlooked North Korean Actor. Retrieved March 1, 2018.
- Mercer, W., Rascagneres, P. (2018, January 16). Korea In The Crosshairs. Retrieved May 21, 2018.
- F-Secure Labs. (2015, September 17). The Dukes: 7 years of Russian cyberespionage. Retrieved December 10, 2015.
- Cymmetria. (2016). Unveiling Patchwork - The Copy-Paste APT. Retrieved August 3, 2016.
- Kaspersky Lab's Global Research & Analysis Team. (2016, July 8). The Dropping Elephant – aggressive cyber-espionage in the Asian region. Retrieved August 3, 2016.
- Hamada, J.. (2016, July 25). Patchwork cyberespionage group expands targets from governments to wide range of industries. Retrieved August 17, 2016.
- Levene, B. et al.. (2018, March 7). Patchwork Continues to Deliver BADNEWS to the Indian Subcontinent. Retrieved March 31, 2018.
- Lunghi, D., et al. (2017, December). Untangling the Patchwork Cyberespionage Group. Retrieved July 10, 2018.
- Meltzer, M, et al. (2018, June 07). Patchwork APT Group Targets US Think Tanks. Retrieved July 16, 2018.
- Hinchliffe, A. and Falcone, R. (2020, May 11). Updated BackConfig Malware Targeting Government and Military Organizations in South Asia. Retrieved June 17, 2020.
- Axel F, Pierre T. (2017, October 16). Leviathan: Espionage actor spearphishes maritime and defense targets. Retrieved February 15, 2018.
- FireEye. (2018, March 16). Suspected Chinese Cyber Espionage Group (TEMP.Periscope) Targeting U.S. Engineering and Maritime Industries. Retrieved April 11, 2018.
- O'Gorman, G., and McDonald, G.. (2012, September 6). The Elderwood Project. Retrieved February 15, 2018.
- Axel F. (2017, April 27). APT Targets Financial Analysts with CVE-2017-0199. Retrieved February 15, 2018.
- DiMaggio, J. (2016, April 28). Tick cyberespionage group zeros in on Japan. Retrieved July 16, 2018.
- Chen, J. et al. (2019, November). Operation ENDTRADE: TICK’s Multi-Stage Backdoors for Attacking Industries and Stealing Classified Data. Retrieved June 9, 2020.
- Svajcer, V. (2018, July 31). Multiple Cobalt Personality Disorder. Retrieved September 5, 2018.
- Positive Technologies. (2017, August 16). Cobalt Strikes Back: An Evolving Multinational Threat to Finance. Retrieved September 5, 2018.
- Positive Technologies. (2016, December 16). Cobalt Snatch. Retrieved October 9, 2018.
- Mesa, M, et al. (2017, June 1). Microsoft Word Intruder Integrates CVE-2017-0199, Utilized by Cobalt Group to Target Financial Institutions. Retrieved October 10, 2018.
- Klijnsma, Y.. (2017, November 28). Gaffe Reveals Full List of Targets in Spear Phishing Attack Using Cobalt Strike Against Financial Institutions. Retrieved October 10, 2018.
- Klijnsma, Y.. (2018, January 16). First Activities of Cobalt Group in 2018: Spear Phishing Russian Banks. Retrieved October 10, 2018.
- CrowdStrike. (2018, February 26). CrowdStrike 2018 Global Threat Report. Retrieved October 10, 2018.
- Giagone, R., Bermejo, L., and Yarochkin, F. (2017, November 20). Cobalt Strikes Again: Spam Runs Use Macros and CVE-2017-8759 Exploit Against Russian Banks. Retrieved March 7, 2019.
- Horejsi, J., et al. (2018, March 14). Tropic Trooper’s New Strategy. Retrieved November 9, 2018.
- Ray, V. (2016, November 22). Tropic Trooper Targets Taiwanese Government and Fossil Fuel Provider With Poison Ivy. Retrieved November 9, 2018.
- Kaspersky Lab's Global Research & Analysis Team. (2018, February 20). A Slice of 2017 Sofacy Activity. Retrieved November 27, 2018.
- Dumont, R. (2019, March 20). Fake or Fake: Keeping up with OceanLotus decoys. Retrieved April 1, 2019.
- Security Response attack Investigation Team. (2019, March 27). Elfin: Relentless Espionage Group Targets Multiple Organizations in Saudi Arabia and U.S.. Retrieved April 10, 2019.
- Microsoft Threat Protection Intelligence Team. (2020, June 18). Inside Microsoft Threat Protection: Mapping attack chains from cloud to endpoint. Retrieved June 22, 2020.
- Livelli, K, et al. (2018, November 12). Operation Shaheen. Retrieved May 1, 2019.
- Moran, N., Oppenheim, M., Engle, S., & Wartell, R.. (2014, September 3). Darwin’s Favorite APT Group [Blog]. Retrieved November 12, 2014.
- Sancho, D., et al. (2012, May 22). IXESHE An APT Campaign. Retrieved June 7, 2019.
- Falcone, R. and Lancaster, T.. (2019, May 28). Emissary Panda Attacks Middle East Government Sharepoint Servers. Retrieved July 9, 2019.
- FireEye Threat Intelligence. (2015, December 1). China-based Cyber Threat Group Uses Dropbox for Malware Communications and Targets Hong Kong Media Outlets. Retrieved December 4, 2015.
- Fraser, N., et al. (2019, August 7). Double DragonAPT41, a dual espionage and cyber crime operation APT41. Retrieved September 23, 2019.
- GReAT. (2019, August 12). Recent Cloud Atlas activity. Retrieved May 8, 2020.
- GReAT. (2014, December 10). Cloud Atlas: RedOctober APT is back in style. Retrieved May 8, 2020.
- Symantec. (2018, March 14). Inception Framework: Alive and Well, and Hiding Behind Proxies. Retrieved May 8, 2020.
- Lancaster, T. (2018, November 5). Inception Attackers Target Europe with Year-old Office Vulnerability. Retrieved May 8, 2020.
- Adamitis, D. et al. (2019, June 4). It's alive: Threat actors cobble together open-source pieces into monstrous Frankenstein campaign. Retrieved May 11, 2020.
- ClearSky. (2019, June). Iranian APT group ‘MuddyWater’ Adds Exploits to Their Arsenal. Retrieved May 14, 2020.
- Ward, S.. (2014, October 14). iSIGHT discovers zero-day vulnerability CVE-2014-4114 used in Russian cyber-espionage campaign. Retrieved June 10, 2020.
- Wu, W. (2014, October 14). An Analysis of Windows Zero-day Vulnerability ‘CVE-2014-4114’ aka “Sandworm”. Retrieved June 18, 2020.
- Li, H. (2013, November 5). McAfee Labs Detects Zero-Day Exploit Targeting Microsoft Office. Retrieved June 18, 2020.