After upgrading to Messaging Gateway 10.7, you find that PDF attachements are triggering an Executable Files content filtering rule. If you are using the default Delete Executable Files Violations content rule, this will cause some PDF attachments to be deleted.
Message Audit Logs will show the PDF file in the "Identified attachment(s)" list, but in the "Suspect attachment(s)" list it will show javascriptfile.js.
Messaging Gateway
The malware scanning engine was improved in Messaging Gateway 10.7 and later releases, which resulted in a change in how files are scanned and embedded items are detected.
The javascriptfile.js is an embedded file within the PDF and is being detected as an executable file type. The filename extension ".js" is what is triggering the rule.
To change this behavior, remove the .js extension from the attachment list used by the content filtering rule that has taken action on the message.
If you are using the default Delete Executable Files Violations content rule and the default Executable Files (default) attachment list, you can address the issue as follows:
Checking file extensions is not always reliable; it is recommended to use True Type file checking to accurately determine a file's actual type.