Hi Praveen,
What kind of outside attack is being referred by you?
As you might know the different modules of DLP, i.e.
- DLP for endpoints- which is for endpoint desktop/laptop.
- DLP for network ie. email, web... (data in motion)
- DLP for storage (data at rest)...used for file server, NAS etc.
So, this is more about data loss or leak from inside to outside- knowingly or unknowingly.
Outside attack and theft of data should be dealt with the help of perimeter security like IPS, firewall, access control etc.
Hope this clarifies.
Let me know if you have further queries.