A method to reduce delays associated with restoring quarantined files is disclosed. In one embodiment, such a method includes maintaining, for a file, a “current” pointer pointing to a current copy of the file and a “backup” pointer pointing to a virus-free backup copy of the file. The method receives an I/O request (a read or write request) to access the file. In response to receiving the I/O request, the method scans the current copy of the file for viruses. In the event a virus is discovered in the current copy, the method modifies the “current” pointer to point to the backup copy. This causes the backup copy to become the new current copy. The method then executes the I/O request with respect to the new current copy. A corresponding system and computer program product are also disclosed and claimed herein.