HTA
HTA files were partnered with maybe IDC files, I forget. Only meant for MS webservers before ASP file format. The HTA had HTML with placeholders (variables) replaced by data from SQL (queries in the paired IDC file). I think that's how it worked, but it's over 15 years ago.
Obviously they are being misused. So there are three design flaws here:
1) OLE inherently is a broken idea.
2) HTA file content
3) That ANYTHING exists and enabled today on Windows to make sense of an HTA file, however loaded.