The DOC extension is used by the Word Word document processor most commonly used in Windows for document files. The DOC format is the standard format of Microsoft Word versions 97 through up Version 2003. As of version 2007 Microsoft introduced the new format DOCX.
In addition to the normal text, a DOC file also contains formatting instructions, formulas, tables, images and possibly also macros. These macros may contain malicious code, which is why you should always do a virus scan before you run them
should install the latest security updates for the Microsoft Office suite.
The Doc format has reached a fairly high popularity, which is why it can be read and created by other office programs for several years. Unfortunately, backward compatibility is not always 100% guaranteed.