Adversaries may bypass UAC mechanisms to elevate process privileges on system. Windows User Account Control (UAC) allows a program to elevate its privileges (tracked as integrity levels ranging from low to high) to perform a task under administrator-level permissions, possibly by prompting the user for confirmation. The impact to the user ranges from denying the operation under high enforcement to allowing the user to perform the action if they are in the local administrators group and click through the prompt or allowing them to enter an administrator password to complete the action.(Citation: TechNet How UAC Works)

If the UAC protection level of a computer is set to anything but the highest level, certain Windows programs can elevate privileges or execute some elevated [Component Object Model](https://attack.mitre.org/techniques/T1559/001) objects without prompting the user through the UAC notification box.(Citation: TechNet Inside UAC)(Citation: MSDN COM Elevation) An example of this is use of [Rundll32](https://attack.mitre.org/techniques/T1218/011) to load a specifically crafted DLL which loads an auto-elevated [Component Object Model](https://attack.mitre.org/techniques/T1559/001) object and performs a file operation in a protected directory which would typically require elevated access. Malicious software may also be injected into a trusted process to gain elevated privileges without prompting a user.(Citation: Davidson Windows)

Many methods have been discovered to bypass UAC. The Github readme page for UACME contains an extensive list of methods(Citation: Github UACMe) that have been discovered and implemented, but may not be a comprehensive list of bypasses. Additional bypass methods are regularly discovered and some used in the wild, such as:

* <code>eventvwr.exe</code> can auto-elevate and execute a specified binary or script.(Citation: enigma0x3 Fileless UAC Bypass)(Citation: Fortinet Fareit)

Another bypass is possible through some lateral movement techniques if credentials for an account with administrator privileges are known, since UAC is a single system security mechanism, and the privilege or integrity of a process running on one system will be unknown on remote systems and default to high integrity.(Citation: SANS UAC Bypass)
Bypass User Account Control
source_name: mitre-attack  url: https://attack.mitre.org/techniques/T1548/002  external_id: T1548.002     source_name: Davidson Windows  description: Davidson, L. (n.d.). Windows 7 UAC whitelist. Retrieved November 12, 2014.  url: http://www.pretentiousname.com/misc/win7_uac_whitelist2.html     source_name: TechNet How UAC Works  description: Lich, B. (2016, May 31). How User Account Control Works. Retrieved June 3, 2016.  url: https://technet.microsoft.com/en-us/itpro/windows/keep-secure/how-user-account-control-works     source_name: SANS UAC Bypass  description: Medin, T. (2013, August 8). PsExec UAC Bypass. Retrieved June 3, 2016.  url: http://pen-testing.sans.org/blog/pen-testing/2013/08/08/psexec-uac-bypass     source_name: MSDN COM Elevation  description: Microsoft. (n.d.). The COM Elevation Moniker. Retrieved July 26, 2016.  url: https://msdn.microsoft.com/en-us/library/ms679687.aspx     source_name: enigma0x3 Fileless UAC Bypass  description: Nelson, M. (2016, August 15). "Fileless" UAC Bypass using eventvwr.exe and Registry Hijacking. Retrieved December 27, 2016.  url: https://enigma0x3.net/2016/08/15/fileless-uac-bypass-using-eventvwr-exe-and-registry-hijacking/     source_name: enigma0x3 sdclt app paths  description: Nelson, M. (2017, March 14). Bypassing UAC using App Paths. Retrieved May 25, 2017.  url: https://enigma0x3.net/2017/03/14/bypassing-uac-using-app-paths/     source_name: enigma0x3 sdclt bypass  description: Nelson, M. (2017, March 17). "Fileless" UAC Bypass Using sdclt.exe. Retrieved May 25, 2017.  url: https://enigma0x3.net/2017/03/17/fileless-uac-bypass-using-sdclt-exe/     source_name: TechNet Inside UAC  description: Russinovich, M. (2009, July). User Account Control: Inside Windows 7 User Account Control. Retrieved July 26, 2016.  url: https://technet.microsoft.com/en-US/magazine/2009.07.uac.aspx     source_name: Fortinet Fareit  description: Salvio, J., Joven, R. (2016, December 16). Malicious Macro Bypasses UAC to Elevate Privilege for Fareit Malware. Retrieved December 27, 2016.  url: https://blog.fortinet.com/2016/12/16/malicious-macro-bypasses-uac-to-elevate-privilege-for-fareit-malware     source_name: Github UACMe  description: UACME Project. (2016, June 16). UACMe. Retrieved July 26, 2016.  url: https://github.com/hfiref0x/UACME     