Create Maldoc_DDE.yar

Malicious_Documents/Maldoc_DDE.yar

+rule Contains_DDE_Protocol
+{
+        meta:
+                author = "Nick Beede"
+                description = "Detect Dynamic Data Exchange protocol in doc/docx"
+                reference = "https://sensepost.com/blog/2017/macro-less-code-exec-in-msword/"
+                date = "2017-10-19"
+                filetype = "Office documents"
+        
+        strings:
+                $doc = {D0 CF 11 E0 A1 B1 1A E1}
+                $s1 = { 13 64 64 65 61 75 74 6F 20 } // !!ddeauto
+                $s2 = { 13 64 64 65 20 } // !!dde
+                $s3 = "dde" nocase
+                $s4 = "ddeauto" nocase
+
+        condition:
+                ($doc at 0) and 2 of ($s1, $s2, $s3, $s4)
+}