If you have lost your important documents due to malware attack then first try to find out the status of your documents because not all the malware delete files in fact they hide it.
In such cases all you need to do is unhide the files. If you are a Window 7 user you can boot to safe mode. Once you are in safe mode go to Windows explorer and select Organize->Folder and search options. Now click View tab and choose “hidden files, folders and drives”. Here you can find all the files that were hidden by the malware.
But this is not always the case, sometimes it really becomes very hard to recover the deleted documents so make a habit to use antivirus and keep it updated always.