Cisco Cisco Email Security Appliance C160 Mode D'Emploi

In the following example, the “executable” pre-defined group of attachments is extended to include more 
attachment names. (Note that this action will not examine the attachments’ file type.)

The 

drop-attachments-by-name

 action supports non-ASCII characters.

The 

drop-attachments-by-name 

action matches the regular expression against the filename captured 

from the MIME header. The filename captured from the MIME header may contain trailing spaces.

In the following example, a message is dropped if the attachment is not an .exe executable filetype. 
However, the filter will not perform any action on the message if there is at least one attachment with 
the file type you want to filter out. For example, the following filter drops any message with an 
attachment that is not an 

 file type:

If a message has multiple attachments, the Email Security appliance does not drop the message if at least 
one of the attachments is an 

.exe

 file, even if the other attachments not 

.exe

 files. 

This 

drop-attachments-where-dictionary-match 

action strips attachments based on matches to 

dictionary terms. If the terms in the MIME parts considered to be an attachment match a dictionary term 
(and the user-defined threshold is met), the attachment is stripped from the email. The following example 
shows attachment drops if words in the “secret_words” dictionary are detected in the attachment. Note 
that the threshold for the matches is set to one: 

The 

attachment-protected

 filter tests whether any attachment in the message is password protected. 

You might use this filter on incoming mail to ensure that the attachments are scannable. According to 
this definition, a zip file containing one encrypted member along with unencrypted members will be 

strip_all_dangerous: if (true) {

                    drop-attachments-by-filetype ('Executable');

                      drop-attachments-by-name('(?i)\\.(cmd|pif|bat)$');

                     }

exe_check: if (attachment-filetype != "exe") {

                   drop();

               }

Data_Loss_Prevention: if (true) {

drop-attachments-where-dictionary-match("secret_words", 1);

}