Systems and methods for preventing leakage of protected document data

Systems and methods for preventing leakage of protected data to unsecured applications and documents may include determining that a first document is a protected document in a managed application, detecting a request to copy protected data from the first document to a system clipboard accessible by unprotected documents, redirecting the protected data to a secure clipboard, determining that a second document is an unprotected document, detecting a request to paste the protected data into the second document, and refraining from pasting the protected data into the second document. The secure clipboard may be implemented by a data leakage prevention (DLP) client. It may be separate from the system clipboard and inaccessible by unprotected documents. Dynamic-link library injection and API hooking may allow the DLP client to intercept clipboard related function calls made by managed applications into the operating system and to transparently change the behavior of the managed application.