How do I use my USB memory stick safely when copying files from and to infected computers?

How do I use my USB memory stick safely when copying files from and to infected computers?

For example, I have a Word-document on my clean laptop's HDD. I right-click on this Word-document, choose to 'Send to...' and choose as target my USB memory stick (without having to open it).

Then, I go to a public computer where I need to have this Word-document printed out. I have to assume this public computer is infected with virus. The USB memory stick has to be opened to view and locate my Word-document, then it's copied onto the public computer's HDD and printed out. I also have a document that I need scanned, so I do that and get a file sent from this infected public computer onto my USB memory stick.

Back home, how should I now safely handle this USB memory stick, and the scanned document from the infected public computer?

I have a laptop and a netbook (my laptop is most important that I keep 100 % clean all the time, the netbook is of secondary importance). I assume I have to open the USB memory stick in order to locate the scanned image. And isn't this the occasion when virus and malware get the opportunity to spread onto my system, the moment I open the root folder on a removable device?

Or I could virus-scan the USB memory stick first, but to be very certain it's clean, I would need to use several different search applications (for virus, for malware etc), right? How certain could I be after doing multiple virus-scans for virus and malware that it's as close to 100 % clean as possible?

Anyhow, if I don't scan it but open on my netbook (which is of secondary security importance), could I then choose to virus-scan only this document (the scanned image) and then choose 'Send to...' to another of my USB memory stick (which I always use only this way, that is, as 'intermediate' transfer tool and I always keep this 2nd USB memory stick empty of files, just for the purpose of momentarily transfering files)?

Finally, I plug this 2nd USB memory stick (which is 100 % clean) into my laptop (which is primary security priority, it must absolutely be kept clean of virus and malware) and open the folder with the scanned image and copy onto my laptop's HDD.

To summarize, one of the two choices would be to do thorough searches with several anti-virus and anti-malware applications etc. on my 1st USB memory stick and trust that all viruses are found. I would then use only this 1st USB memory stick, on both my netbook and my laptop.

Or, the second choise is that I use my netbook and my 1st USB memory stick as 'higher-risk' devices, and my laptop and 2nd USB memory stick as 'secure' devices.

A final question: I've already disabled auto-play on my 'secure' laptop. I wouldn't need to disable auto-play also on my 'higher-risk' netbook, would I? My 'higher-risk' netbook would auto-play my 'secure' 2nd USB memory stick, but in that moment no virus or malware would be given the opportunity to spread onto my 2nd USB memory stick, would it? It must be the other way around, virus and malware could only spread from the 2nd USB memory stick onto netbook's HDD during auto-play.

Or do I make everyting too complicated? Is there no risk for spreading of virus and malware when I open root folder of my infected 1st USB memory stick?

Also, is there any difference between different OS, such as Windows XP, Linux Kubuntu, Windows Vista, and Windows 7?
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Mal OsborneAlpha GeekCommented:
USB keys are cheap, and it is possible to purchase one with a hardware write protect switch.  Just remember to flip it before plugging into a suspect machine.

I would suggest that you keep the USB stick write protected allways when ýou use it i in unsafe area (You can still locate and print documents from the stick). If you need something from outside world sent it to you bvy email asn an attachment

Best wishes HPu
Get NOD32 Antivirus ( Its one of the best AV available.

Coming to your qn. if you have Nod installed on your laptop/netbook and once you insert a infected USB it will either quarantine/clean the file automatically. It doesn't allow the virus to spread to your computer.

Think nod32 can be used on 2 machines with single user license. So you can have it on your laptop and netbook.
IT Pros Agree: AI and Machine Learning Key

We’d all like to think our company’s data is well protected, but when you ask IT professionals they admit the data probably is not as safe as it could be.

hermesalphaAuthor Commented:
I'm going to check my Kingston Data Traveler 4 GB (Kingston DTI/4GB) later if it has a built-in write protect switch (I'm trying to permanently delete the infections that were found, but can't do it with my Eset Smart Security). How do I find that out?

My second Kingston is also a DataTraveler 4 GB (Kingston DataTraveler 101). Do you know if this or the first Kingston has a built-in write protect switch? I might return the second Kingston to the store where I bought it if the first one has a write protect switch.

If the public computer has internet access, why not e-mail yourself the document and avoid the USB stick all together :)

Hi hermesalpha

It's quite difficult to find a write protect flash drive, but there are some write-protect models in some of the Maxell & Imation ranges. the Maxell has a handy LED indicator.

(I am an Eset reseller), A single Nod32 licence cannot be used on 2 computers. Nod32 will not reliably protect you against flash drive infection attempts. Turning off autoplay will not protect you from a Flash drive virus attack.

My recommendation is to assume that any computer you do not own is infected. Buy a write-protected USB flash drive to use externally. protect both your computers with Prevx.
The best practice AFAIK is to create a readonly hidden system files RECYCLER and RECYCLER and also create hidden system readonly autorun.inf folder. This simple action will prevent most viruses from start automatically from your USB drive. Then you can safely remove all suspicious files from your flash to make it clean again witout using any AV software. Best wishes.

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The only thing you need is a updated antivirus software, It will detect infection on access meaning that when you plug-in the usb stick on your laptop, it will prevent the infection. Free option I can recomend is avast!. Scan the usb stick on the netbook before you use it on the laptop this way you can be safer
Write protected usb key can't get infected, you may also should take a look a this:

Best regards
windows 7 gives a much better protection than xp and Vista.
but if you access infected PC's - you need to scan the stick.
i suggest to use one of these, in combination with your AV :
     Spybot :                         MBAM            Combofix                                       download              check the log
my suggestion: copy only the files that you are working in the USB drive and format them when finish.

hermesalphaAuthor Commented:
Need a little clarification: with a write protect USB stick, if I need to scan a document and then move the scanned image onto the write protect USB stick, that is not possible is it? Or can I manually select files to excempt from write protect?
you can not to choose such files. you can not write to readonly drive
Read the below links
How do I delete a quarantined file? (3.0)

How do I change the scanner's default response to a virus detection?

Use the settings in
It will direclty delete the infected file once you insert your USB. Having write protected switch in USB is optional but having a best anti virus is mandatory.

I have been in your shoes many times and NOD32 took care of the rest. Also keep your virus definitions upto date.
Flash Disinfector is a help
On any device like that(removable) run flash Disinfector
-Download to desktop
-Run it
-Follow prompts
-When asked, plug in removable usb device
-It will prompt when scan is finished
-Repeat for next removable usb

>The threats which are detected reside on memory stick?
Can you post Eset's logfile relavant to threats that it can't remove
hermesalphaAuthor Commented:
solni6 and Mr_Grumpy,

Are you talking about the same device? Read only drive and write-protected USB flash drive with swítch?

I can't see why I couldn't just use the switch to make it writable when I need to write to it? Isn't that the whole purpose? To be able to choose whether having it in write-only or read mode,  using the switch?

Or is it one-time write only? But can't I use it thereafter?
yes we are talking about the same device. but as soon as you swith it writable on the infected computer it will poison the drive :) it also depends on drive if you can swith it rw/ro online
so in fact,  a write protect switch does not help, if anything has to be written to it.
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