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How do I remove a virus from a memory card?


I have been having problems with hackers and viruses and the like
and have one right now that avast will not find and superantispyware
wont find either. I’ve tried in the past a range of virus scanners for
it but to no success. its on a camera disc little SD memory card, and
tries to spread to my hard drive and any other media anytime i connect

I was wondering what steps you would take in my position?

There are a few things I would do, and they start out pretty

With any disk that isn’t your system disk you have a wonderful
opportunity to get rid of viruses and spyware fairly quickly and

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Reformat the card.

Presumably you have a card reader, and presumably that card, when
inserted, appears as another drive on your computer.

Reformat it. Remove any data you want to keep first, but then
reformat it.

“Reformat it. Remove any data you want to keep
first, but then reformat it.”

That will erase everything from the card. Data. Viruses.
Spyware. Everything.

If for some reason you cannot reformat it on your computer, then
once again, copy off the data you want to keep, and use your camera or
other device to reformat it; most have this as an option.

We talk about “reformat and reinstall” as a last resort, or in some
cases the only resort, to curing an infection on your system drive. The
problem is that while this does eradicate the infection by erasing
everything, it erased everything, including your operating
system. You now have to reinstall, or perhaps recover from a backup
image that was created prior to the infection.

With other drives we have a little bit more flexibility. It still
really is “reformat and reinstall”, but typically the “reinstall” part
is significantly less of a problem. You can copy all the pictures off
of your camera’s SD card, and reformat it without much effort. Even
other drives, such as external hard drives or internal hard disks, can
be treated the same way, though in these cases the problem is often
where to copy the data, and making sure you also don’t copy the

So that gets it off of your SD card.

But I’m still concerned.

Most viruses insert themselves into your system. Specifically, they
copy files onto your system drive, and insert themselves in various
system-related places like the registry. It’s unclear how you’ve been
clearing this off once you’ve determined you’ve become infected. In
fact, it sounds like the tools you have at hand haven’t been able to
clean it from your SD card, so I don’t see how your system isn’t still
infected as well.

It’s quite possible, then, that even after formatting your SD card,
your still-infected system might not put the infection right back.

Unfortunately I don’t have a silver bullet for this situation. Not
all anti-malware programs catch every possible malware. I would, in
your shoes, run a variety of those tools, both anti-virus and
anti-spyware, to attempt to clear off the infection.

If that still doesn’t work, then you’re faced with only one

Backup, reformat your system drive and reinstall everything.

Do this

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33 comments on “How do I remove a virus from a memory card?”

  1. Hello Leo,
    Thanks so much for the post of the question and answer! :)
    I do have a card reader on my computer. I do have the option to reformat it. I also saw that I forgot to list how I know I am not infected by it right now, I have a wonderful solution on my system called deepfreeze. what it does is freeze the whole system in one state and reboots, then I can do whatever I like and if I see something like a virus I restart and get rid of it with a reboot. unfortunately without it running 24/7 I get attacked and have had to reformat once every 2-3 weeks for the last few months, even with running the anti virus firewall router anti spyware.. just visiting sites like youtube and AOL.
    The tools I use to get rid of viruses are as follows- avast anti virus, avg, super anti spyware, smitrem, smitfraud fix, kill process, spybot s&d ccleaner, coffee cup privacy cleaner, deepfreeze… none running at the same time i.e. virus shields or firewall’s. some how this virus got onto my system at one point and put itself on my camera disc before I reformatted my hard drive.
    and with reformatting the whole camera drive I got some pictures I just cant replace. so im wondering if there’s a way to find out which files are infected or if they all are
    I believe I know who this particular virus is from an old ex friend, is there any way to maybe decode it enough to get it to an anti virus company so they can fix it with they’re software?
    Thanks so much Leo !! :)

  2. Patrick: copy your pictures to your computer, then burn them to a CD. Take the CD to a friend’s PC to make sure you have the pictures. Then reformat the memory card on the camera, as Leo told you to do.

    Also: pick one anti-virus program and live with it.

  3. Gord, But what if this particular virus embeds itself into a picture (jpeg, etc.)? Wouldn’t it spread to the friend’s computer?

  4. Leo, there’s something he needs to do before he sticks the card into his computer to reformat it: TURN OFF AUTORUN! That’s presumably how the virus spreads in the first place, with an “autorun” program on the card. You did discuss this in this article, but maybe you need a separate one on how to turn autorun off, and why it’s such a good idea….

  5. The way i see it is that some viruses are easily destroyed in safe mode. If you can load everything on your card onto your local hardrive and switch to safe mode. You also need to find the name of the virus you can, if you can find information about the virus; its behaviour etc, the easier you can get rid of it. I would also like to point out that formatting a hardrive every now and then kind of shortens its life span.

  6. I have got a canon camera with 4 gb memory card.
    Now if i put the card in a card reader it is showing the icon down on the desktop, but not listing the drive in My Computer or showing any contents. Is it affected by a virus? If so how to remove it?

  7. I have brought new 4GB Micro sd card for my mobile phone , but the card has now got virus in it , if i format also it is not going out , what should i do.
    How can i remove virus from it.

    How do you know it has a virus? Formatting an SD card will remove everything, including any viruses. You could be getting re-infected if your machine also has that virus, though.

    – Leo
  8. Hi I have compaq prasario c772tu with win xp sp2, when i connect any removable device, the system shows there is no device in drive please insert a dis, but works. how can i solove the problem

  9. Hi i have brought 4gb micro scandisk memory card for my mobile ,but its not working if i take photo it shows format not supported if i create folder in it the format of folder changes , anything copied from PC to card there is change in the format . i cant delete the folder created also. I tried to format it but still its the same.

  10. ok! this articles was nor helpfull to me! my merory ard is on my mobile phone. I FORMATTED IT MANY TIMES FROM MY MOBILE. but when i join it to computer it tells that the disk is not formatted and i try to format my card from computer but then tells” the formatt is incomplete” . And my phone also shut off and on automatically when inserting card on toit. please help me.mail me at [email address removed]

    Did you consider that perhaps the memory card is bad?

    – Leo
  11. hei.. i juxt want to axk that wheneve i tried to reformat me micro sd card it says unable to complete. when i tried to erase all the datas. it will only be gone a few seconds. and when i still inserted it the data still remains. i know it has virus but how can i re4mat it?

  12. the memory card was working normaly on my phone suddenly it starts to show every time i want to go to memory card that ” memory card not formated do u want to format memory card ” & i am afraid to format it so that i will lose all my data
    so leo what is the solution

  13. hi, pls help me, my mmc memory card was eaten by a virus, i’m not familiar with the virus but i think it was a comwarrior that comes into mutation that makes it even stronger that my avast anti virus can’t even rid of it. it just says unreadable or unknown format. it can’t even be formatted either… please help me.

  14. i agree with u Leo in what u said but there are one comment why we cant not remove the virus directly without format the card ,as i know there memory card is like the excess hard on the computer .
    then there is no problem to treat it with the same way

  15. how to remove a malware from memory card as i tried to format it but its not allowing me to do that it has also affected my computer and im using avira antivirus but it also cant remove it,plz help me out…

  16. i agree with u Leo in what u said but there are one comment why we cant not remove the virus directly without format the card ,as i know there memory card is like the excess hard on the computer .
    then there is no problem to treat it with the same way

  17. i want to remove virus from my memory card but the virus is not leting me to do it. any antivirus is not working and when i delete files from the memory card it is deleted afterwards it is again recovered…

  18. i tried to format it but it tells format completed but the things remains in memory card……… they are not deleted pls help…..

    Either you’re not formatting what you think you are, or there’s another problem – perhaps your machine is infected and immediately re-infecting the memory card when the format is complete. Make sure that the format is NOT “quick”.


  19. my mmc card doesnt delete or formating the files. please help me to format or to move the virus on my mmc card

    I’d have to know what happens when you try. No way for me to help with the information given, I’m afraid.


  20. when i take any file from my pc after formatting after 2-3 weeks in my video folder of my mmc sd card a file appears as ‘dummy.tmp’ which does’t open’s in the phone when i delete it many problems appears as like the sound does’t change untill i restart and again after 2-3 weeks the file comes back.Is it a virus?

  21. @Jean
    If you are using the format command, Right clicking on the memory card in Windows Explorer and choosing format you should be able to format the card without any problems. If you make sure that the write protect tab is in the unlock position, you should be able to format the card unless there is physical damage to the card or card slot.
    Since you mention that a file is unable to be erased, I’ll assume you are deleting files and not actually formatting the card. There is a free utility that allows you to delete locked files called Unlocker Assistant which works in the vast majority of cases.

  22. I know i can reformat my SD card but how do i get my pictures off first? I know they are there but i cant see them and access them? Norton virus scan scans them but I can’t find them. What can i do?

    Perhaps try Recuva.

  23. my casio exilim got virus and im unable to see my files everytime i plug in the cam on the computer. Its only contain of virus files that can’t open. what can i do to solve this kind of problem?


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