Word Document (DOC)
The DOC file format (document file format) usually has the .doc extension. Mostly these documents belong to Microsoft Word software files. However, other text editing software can be used to display these files (including WordPad, WordPerfect, OpenOffice and others).
The DOC file format should not be confused with DOCX.
MS Word documents of version 97 (and probably earlier) begin with the file signature (in hexadecimal) d0cf11e0a1b11ae1 . This signature signifies the file to be an OLE Compound File (AKA Compound Document File or Compound Binary File)
The OLE Compound File has no distinct footer and a can be considered a file containing a FAT like file system.
The Word document format is places on top of the OLE Compound File.
The object stream of a word documents contains the string "Word.Document" with some version.
Versions 97/2000 encrypt documents with a very weak algorithm. This password scheme can be broken easily by several different products and it is possible to decrypt the contents without discovering the password. This is done by testing all 1,099,511,627,776 possible keys. Ultimate Zip Cracker by VDGSoftware is one utility that can perform this decryption.
Microsoft Compound Document File Format (This is actually the OpenOffice specification)
Be warned this file contains at least one error: the directory entry name length is a size in bytes not in characters.
On a unix-like machine try this command to extract strings from a .doc file:
cat /tmp/test.doc | tr -d \\0 | strings | more
(where /tmp/test.doc is the path to your .doc file)