Add module doc for symantec_brightmail_ldapcreds

Author: wchen-r7

documentation/modules/auxiliary/scanner/http/symantec_brightmail_ldapcreds.md

@@ -0,0 +1,40 @@
+Symantec Messaging Gateway is an all-in-one appliance to secure email with real-time antispam,
+antimalware, targeted attacks, content filtering, data loss, and email encryption.
+
+The management console of SMG can be used to recover the AD password by any user with at least
+read access to the appliance, which could potentially permit leveraging unauthorized, elevated
+access to other resources of the network.
+
+Authentication is required to use symantec_brightmail_ldapcreds. However, it is possible to see
+SMG with using the default username **admin** and **symantec**.
+
+
+## Vulnerable Application
+
+Symantec Messaging Gateway 10.6.0 and earlier are known to be vulnerable.
+
+symantec_brightmail_ldapcreds was specifically tested against 10.6.0 during development.
+
+## Verification Steps
+
+These verification steps assume you already have access to the vulnerable version of
+[Symantec Messaging Gateway](https://www.symantec.com/products/threat-protection/messaging-gateway).
+During the development of symantec_brightmail_ldapcreds, Symantec was still providing 10.6.0 as a trial.
+
+**Installation**
+
+The 10.6.0 installation guide can be found [here](https://symwisedownload.symantec.com//resources/sites/SYMWISE/content/live/DOCUMENTATION/9000/DOC9108/en_US/smg_10.6_installation_guide.pdf?__gda__=1465490103_20360f5503fd3ef6ce426bd541fd2109)
+
+Make sure you remember your username and password for Symantec Messaging Gateway before using
+the module.
+
+**Using the Module**
+
+Once you have the vulnerable setup ready, go ahead and do this:
+
+1. Start msfconsole
+2. Do: ```use auxiliary/scanner/http/symantec_brightmail_ldapcreds```
+3. Do: ```set RHOSTS [IP]```
+4. Do: ```set USERNAME [USERNAME FOR SMG]```
+5. Do: ```set PASSWORD [PASSWORD FOR SMG]```
+6. Do: ```run```