Format a probably infected USB, is it safest Ubuntu live or Ubuntu installed?
I have an USB drive that probably is infected. I have a PC where currently I have not any partition, just an "empty" PC and I have a CD with Ubuntu 22.04. I would like to copy USB data, format the USB and copy data back to USB.
To format the USB I will use dd:
sudo dd if=/dev/zero of=/dev/sdX bs=1k count=2048
I took this from here: https://askubuntu.com/a/185827
I was thinking of these ways to protect the formatted USB when I will insert it back to copy back the data:
First way: (Ubuntu Live and an empty partition)
- Launch Ubuntu 22.04 Live with the CD
- Create an empty partition on my PC just to put data
- Mount the partition
- Insert the USB and copy data to partition
- Format the USB
- Restart the Live
- Mount the partition where I copied data before
- Insert the USB and copy back data from the partition to the USB
I think that the problem of this way is that: The malware could to exploit an Ubuntu Live vulnerability and replicates itself from the USB to the partition, then when I will restart the live and mount the partition, it will replicate back from partition to the formatted USB. Also, I think that when you run Ubuntu Live, you don't have latest security update.
Second way: (Using installed Ubuntu)
- Install Ubuntu 22.04 on the PC and start it
- Insert the USB and copy data on the user Home
- Format the USB
- Restart the OS
- Insert the USB and copy back data from Ubuntu to the USB
In this way, I think that the problem is: The malware could to exploit an Ubuntu 22.04 vulnerability and replicates itself from the USB to the OS, then it will infect the OS and when I will insert the formatted USB back, it will replicate back from the OS to the formatted USB.
Third way: (Use installed Ubuntu and the live)
- Install Ubuntu 22.04 on the PC and start it
- Insert the USB and copy data on the user Home
- Shutdown the OS
- Start Ubuntu Live with the CD
- Insert the USB and format it without to mount the Ubuntu Partition
- Restart the Live
- Mount the Ubuntu Partition (the partition where Ubuntu is installed)
- Insert the USB and copy back data from the Ubuntu partition to the USB.
I think this is the longest but safest way, but I don't know.
Which is the safest way? Is there another way?
Yes, I know it's very paranoid question, but I want to try to make 99.9 % sure that the USB will not be reinfected back once I formatted it and copied back its data to it.
