Adversaries may abuse Regsvcs and Regasm to proxy execution of code through a trusted Windows utility. Regsvcs and Regasm are Windows command-line utilities that are used to register .NET [Component Object Model](https://attack.mitre.org/techniques/T1559/001) (COM) assemblies. Both are binaries that may be digitally signed by Microsoft. (Citation: MSDN Regsvcs) (Citation: MSDN Regasm)

Both utilities may be used to bypass application control through use of attributes within the binary to specify code that should be run before registration or unregistration: <code>[ComRegisterFunction]</code> or <code>[ComUnregisterFunction]</code> respectively. The code with the registration and unregistration attributes will be executed even if the process is run under insufficient privileges and fails to execute. (Citation: LOLBAS Regsvcs)(Citation: LOLBAS Regasm)
Regsvcs/Regasm
source_name: mitre-attack  url: https://attack.mitre.org/techniques/T1218/009  external_id: T1218.009     source_name: MSDN Regsvcs  description: Microsoft. (n.d.). Regsvcs.exe (.NET Services Installation Tool). Retrieved July 1, 2016.  url: https://msdn.microsoft.com/en-us/library/04za0hca.aspx     source_name: MSDN Regasm  description: Microsoft. (n.d.). Regasm.exe (Assembly Registration Tool). Retrieved July 1, 2016.  url: https://msdn.microsoft.com/en-us/library/tzat5yw6.aspx     source_name: LOLBAS Regsvcs  description: LOLBAS. (n.d.). Regsvcs.exe. Retrieved July 31, 2019.  url: https://lolbas-project.github.io/lolbas/Binaries/Regsvcs/     source_name: LOLBAS Regasm  description: LOLBAS. (n.d.). Regasm.exe. Retrieved July 31, 2019.  url: https://lolbas-project.github.io/lolbas/Binaries/Regasm/     