GP;

  CS-MARS does not natively support the Imperva firewall.  This means out-of-the-box, CS-MARS cannot parse any messages received by this device.  You could create your own custom device using the CS-MARS Device Support Framework (DSF).  This requires creating custom parsers for the various messages you wish to have CS-MARS parse and map to a CS-MARS event.  This process is outlined here:

http://www.cisco.com/en/US/docs/security/security_management/cs-mars/6.0/user/guide/combo/cfgCustm.html

  There is also a custom device package sharing forum here in the community:

https://supportforums.cisco.com/community/netpro/security/mars-pkg?view=discussions

  I do not currently see any discussion in that forum regarding the Imperva firewall.

Scott