Yes, you are correct, ASA5585-X does not support CSC module.
For anti malware, anti spyware and web filtering capabilities, you can either use Cisco Ironport WSA appliance, OR you can also opt to go for Cisco ScanSafe cloud solution. Both solution provides anti malware, anti spyware and web filtering capabilities.
Here are more information on the product for your reference:
Cisco Ironport WSA:
http://www.cisco.com/en/US/products/ps10164/index.html
Cisco ScanSafe:
http://www.cisco.com/en/US/products/ps11720/index.html
Hope this helps.