A file format in Microsoft Word 2007 and later versions, which replaced DOC. DOCX files are archives containing XML-marked text and other document data that can be interpreted by a text editor.

Since 2006, DOCX is an open format, like the whole family of Microsoft Office formats. In 2008, the format was certified to the ISO/IEC IS 29500:2008 standard.

Files of this type are able to run scripts when opened. This can be exploited by cybercriminals to insert malicious code into a document.