Removing virus from USB

Discussion in 'Mac Basics and Help' started by bingo888, Apr 30, 2011.

  1. bingo888 macrumors newbie

    Apr 30, 2011

    I'm new to this forum and would like help on a small matter.

    I am both a PC and Mac user. I recently got a virus on my PC and my USB stick, which was also attached, seem to have been infected with the same thing. I know this will not affect my Mac (Leopard) and i'm thinking about running it through Disk Utility and format it to FAT (with a 7-pass erase to be safe).

    My question is will formatting with D.U. be sufficient? Will this completely remove the virus from the USB? I've been looking around but cannot find a definite answer. Some say formatting will only remove the link to the folders containing the virus, but the virus can linger in there somewhere. There are a variety of specialized Windows programs that can be used to erase viruses and I am, therefore, unsure if a free program like Disk Utility is good enough.

    Anyone have any input to this? I want to ensure all traces of this virus is completely removed so my PC does not get reinfected.

    Any help is greatly appreciated.

  2. GGJstudios macrumors Westmere


    May 16, 2008
  3. -aggie- macrumors P6


    Jun 19, 2009
    Where bunnies are welcome.
  4. chrono1081 macrumors 604


    Jan 26, 2008
    Isla Nublar
    As others have stated, yes. I do this all the time at work to remove viruses on thumb drives if I can see the virus files.
  5. I AM THE MAN macrumors 6502

    Apr 10, 2011
    As all the repliers have said, yes it will remove the virus. Just save any of your IMPORTANT files onto the mac and keep them there...and erase everything on the USB by reformatting it.
  6. OldSchoolMacGuy Suspended


    Jul 10, 2008
    Only issue with saving the files to the Mac would be if the files contain the virus or the virus has copied itself to the files. Things would be fine if they're only used on the Mac but sharing them back to your PC could cause issues.
  7. MarkMS macrumors 6502a

    Aug 30, 2006

    This is why I advocate for antivirus apps for Mac. I use ClamXAV, it's free and uses the open source ClamAV engine that Apple uses for virus filtering on OS X Server. It's main use, on my machine, is to prevent the spread of Windows-based threats to my buddies on PCs. It's also great that it protects from known OS X threats too.
  8. zaboo9 macrumors newbie

    Feb 5, 2014
    Does formatting erase MBR?

    - I had a similar situation where I plugged an NTFS Windows imaging USB flash drive I use into a computer with malware, however I didn't hit F12 quick enough on startup to boot from the imaging USB and the Windows login screen appeared, which could have potentially infected the USB at that point.

    Being safe I used my MAC and the Disk Utility 'Erase' function to format the USB to fat32.

    My question is, did formatting it to fat32 TRULY erase EVERYTHING, specifically the Master Boot Record? I specifically want to know this in case there was a virus in the Master Boot Record of the USB.
  9. MacUser2525 macrumors 68000


    Mar 17, 2007

    If you want to be certain go to the partition tab of the disk when its selected. Then choose the option button select the GUID format and apply. Once that is done go back to the options select MBR FAT32 for formatting and you have a newly partitioned and formatted drive that has erased and overwritten the former MBR that was on it. BTW rather than the necro thread revival it is best to start your own new thread referencing the old thread with a link to it in the new if necessary.
  10. phrehdd, Feb 6, 2014
    Last edited: Feb 6, 2014

    phrehdd macrumors 68040


    Oct 25, 2008
    This is pretty sound advice. Some people are unaware that a virus can also be in the master boot sector (record) and until that sector is dealt with, it can re-occur even if you erase files. By removing the master boot sector, and then creating a new one later, you can consider your thumb drive "safe." Kudos to you for pointing out the less obvious and with a practical solution.
  11. MacUser2525 macrumors 68000


    Mar 17, 2007
    Thanks I always try to give sound advice when posting.

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