Adversaries may abuse msiexec.exe to proxy execution of malicious payloads. Msiexec.exe is the command-line utility for the Windows Installer and is thus commonly associated with executing installation packages (.msi). The Msiexec.exe binary may also be digitally signed by Microsoft.
Adversaries may abuse msiexec.exe to launch local or network accessible MSI files. Msiexec.exe can also execute DLLs. Since it may be signed and native on Windows systems, msiexec.exe can be used to bypass application control solutions that do not account for its potential abuse. Msiexec.exe execution may also be elevated to SYSTEM privileges if the
AlwaysInstallElevated policy is enabled.
Duqu has used
|Disable or Remove Feature or Program
Consider disabling the
|Privileged Account Management
Restrict execution of Msiexec.exe to privileged accounts or groups that need to use it to lessen the opportunities for malicious usage.
Command arguments used before and after the invocation of msiexec.exe may also be useful in determining the origin and purpose of the MSI files or DLLs being executed.
Monitor DLL/PE file events, specifically creation of these binary files as well as the loading of DLLs into processes. Look for DLLs that are not recognized or not normally loaded into a process.
|Network Connection Creation
Monitor for newly constructed network connections that are sent or received by untrusted hosts.
Use process monitoring to monitor the execution and arguments of msiexec.exe. Compare recent invocations of msiexec.exe with prior history of known good arguments and executed MSI files.