http://www.reuters.com/article/2014/12/02/us-sony-cybersecurity-malware-idUSKCN0JF3FE20141202
The report said the malware overrides all data on hard drives of computers, including the master boot record, which prevents them from booting up."The overwriting of the data files will make it extremely difficult and costly, if not impossible, to recover the data using standard forensic methods," the report said.
The document was sent to security staff at some U.S. companies in an email that asked them not to share the information.
I notice the strange mis-use of verbiage. It is non-technical in the the use of "overrides" which is an "authority, power, cancel, etc." a decision of a lower subordinate. Not a technical term at all. The next paragraph uses a proper technical term which can be appropriate use for the destruction of data: "overwriting" with nonsense data.
Then we find that someone selected that only certain companies were notified of this danger. Who made that selection and on what criteria? Then we find that the selected companies were asked (read "told") to keep that information quiet! Again, why?
This strikes me as politically selective and not good. Who was left with their data hanging in the wind at risk?