I think it can't because malware need a path to infect the files.
Yes, but malware can do other things to propagate than infect files. For example, there is malware that achieves persistence by modifying the MBR.
A master boot record (MBR) is a special type of boot sector at the very beginning of Partitioned computer mass storage devices. Source
So its a part of partitioned Drive.It can't infect the un-partitioned drive. Am i Right? Didier Stevens.
And let's not forget our popular fileless fiend - Poweliks.
Poweliks is a threat located in a registry key.
All registry Data is stored in System Drive which is Partitioned.
Nothing it can do to non partitioned Drive.
Let me clarify I talking about a Partition which has no Letter which means we can't do anything inside to that partition (Data transfer,Changes in files,etc..)