<SOLVED> scan files and libre, microsoft office

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kost
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<SOLVED> scan files and libre, microsoft office

Post by kost »

I want to ask two questions.

1) My friends laptop is running windows. His laptop has infected (spyware, trojan, virus etc). He wants to install linux mint. First he wants to copy his files from windows in external device. After the installation of linux mint in his laptop he wants to move all his files from external device to his laptop. Do I need to scan the files before move the files to the linux enviroment?

2) Can libre office open all extensions of microsoft office files? Can save libre office file in microsoft office extension so I can open it with microsoft office?
Last edited by kost on Sat Sep 20, 2014 8:36 am, edited 1 time in total.
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nomko

Re: scan files and libre, microsoft office

Post by nomko »

kost wrote: 1) My friends laptop is running windows. His laptop has infected (spyware, trojan, virus etc). He wants to install linux mint. First he wants to copy his files from windows in external device. After the installation of linux mint in his laptop he wants to move all his files from external device to his laptop. Do I need to scan the files before move the files to the linux enviroment?
First of all, Linux is not vulnerable for any malicious software written for Windows. However, any infected files will be stored on a Linux drive as it is, meaning including with the code that infected the files (i.e.: virus, trojans). To make sure which files aren't infected and which are, yes it doesn't do no harm to scan those files. Just leave them on the excternal device first during scanning.
kost wrote: 2) Can libre office open all extensions of microsoft office files? Can save libre office file in microsoft office extension so I can open it with microsoft office?
Yes and yes, only some users experienced problems with document layoutsand excel macro's. But a normal MS Office document can be opened with LibreOffice and saved as a MS Office file. There's another alternative: WPS Office which has a much better support for MS Office files.
kost
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Re: scan files and libre, microsoft office

Post by kost »

nomko wrote:
kost wrote: 1) My friends laptop is running windows. His laptop has infected (spyware, trojan, virus etc). He wants to install linux mint. First he wants to copy his files from windows in external device. After the installation of linux mint in his laptop he wants to move all his files from external device to his laptop. Do I need to scan the files before move the files to the linux enviroment?
First of all, Linux is not vulnerable for any malicious software written for Windows. However, any infected files will be stored on a Linux drive as it is, meaning including with the code that infected the files (i.e.: virus, trojans). To make sure which files aren't infected and which are, yes it doesn't do no harm to scan those files. Just leave them on the excternal device first during scanning.
kost wrote: 2) Can libre office open all extensions of microsoft office files? Can save libre office file in microsoft office extension so I can open it with microsoft office?
Yes and yes, only some users experienced problems with document layoutsand excel macro's. But a normal MS Office document can be opened with LibreOffice and saved as a MS Office file. There's another alternative: WPS Office which has a much better support for MS Office files.

1) So you mean to scan the external device from windows enviroment and then scan the external device from linux enviroment and then move the files to laptop. Right?
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nomko

Re: scan files and libre, microsoft office

Post by nomko »

kost wrote: 1) So you mean to scan the external device from windows environment and then scan the external device from Linux environment and then move the files to laptop. Right?
No, if Windows is infected with viruses and trojans and malware, etc. it is better to move all the files to an external device and install Linux Mint on the laptop. Thus to avoid that, while scanning the files for any malicious software and/or infected files, other files get infected.

It is not wise to scan for malicious software and infected files from an infected operating system!

After installing Linux Mint you can install the following anti-virus tool: ClamAV and the GUI interface package ClamTK. ClamAV is able to scan both Linux file systems and Windows file systems. And as said above, Linux cannot be infected by malicious software meant for Windows. You can even move the files to a folder you created manually in the /home folder (i.e.: make a folder called infected files) and let ClamAV scan that folder only. This also avoids that any malicious software will get activated since it cannot be activated on a Linux file system.
kost
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Re: scan files and libre, microsoft office

Post by kost »

nomko wrote:
kost wrote: 1) So you mean to scan the external device from windows environment and then scan the external device from Linux environment and then move the files to laptop. Right?
No, if Windows is infected with viruses and trojans and malware, etc. it is better to move all the files to an external device and install Linux Mint on the laptop. Thus to avoid that, while scanning the files for any malicious software and/or infected files, other files get infected.

It is not wise to scan for malicious software and infected files from an infected operating system!

After installing Linux Mint you can install the following anti-virus tool: ClamAV and the GUI interface package ClamTK. ClamAV is able to scan both Linux file systems and Windows file systems. And as said above, Linux cannot be infected by malicious software meant for Windows. You can even move the files to a folder you created manually in the /home folder (i.e.: make a folder called infected files) and let ClamAV scan that folder only. This also avoids that any malicious software will get activated since it cannot be activated on a Linux file system.


So first I will move the files from infected laptop to the usb . Then I will install linux in the laptop and I will connect the usb and I will scan with clamtk + av the usb. Last I will move the files to the laptop. Is it what are you saying?

There are some rare infections that can run both linux and windows enviroment.
How clamtk+av will scan only for viruses what about other infections trojan,spyware etc?
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nomko

Re: scan files and libre, microsoft office

Post by nomko »

kost wrote:So first I will move the files from infected laptop to the usb.
Yes, as i explained, it is not smart to scan for infected files using an infected operating system (in your case Windows).
kost wrote: Then I will install linux in the laptop and I will connect the usb and I will scan with clamtk + av the usb.
Yes, doing so you avoid scanning from an infected system and you also secure yourself from any infected files trying to infect you newly installed operating system (Linux).
kost wrote: Last I will move the files to the laptop. Is it what are you saying?
After you scanned them you can move the non-infected files to your laptop. Most probably that your infected files will be moved to a quarantine directory of ClamAV.
kost wrote: There are some rare infections that can run both linux and windows enviroment.
How clamtk+av will scan only for viruses what about other infections trojan,spyware etc?
Which "rare infections" could also infect Linux?? If it is true you're saying you have a big scoop!Please provide us with links/examples to verify!!
kost
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Re: scan files and libre, microsoft office

Post by kost »

nomko wrote:
kost wrote:So first I will move the files from infected laptop to the usb.
Yes, as i explained, it is not smart to scan for infected files using an infected operating system (in your case Windows).
kost wrote: Then I will install linux in the laptop and I will connect the usb and I will scan with clamtk + av the usb.
Yes, doing so you avoid scanning from an infected system and you also secure yourself from any infected files trying to infect you newly installed operating system (Linux).
kost wrote: Last I will move the files to the laptop. Is it what are you saying?
After you scanned them you can move the non-infected files to your laptop. Most probably that your infected files will be moved to a quarantine directory of ClamAV.
kost wrote: There are some rare infections that can run both linux and windows enviroment.
How clamtk+av will scan only for viruses what about other infections trojan,spyware etc?
Which "rare infections" could also infect Linux?? If it is true you're saying you have a big scoop!Please provide us with links/examples to verify!!
There is not proof I was thinking if there are this infection that running both in linux and windows.
You said that "It is not wise to scan for malicious software and infected files from an infected operating system!". If I scan in an infected windows system will the infection spread more faster in all hard drive?
Linux for Ever :D
nomko

Re: scan files and libre, microsoft office

Post by nomko »

kost wrote: There is not proof I was thinking if there are this infection that running both in linux and windows.
You posted this remark: There are some rare infections that can run both linux and windows enviroment.

You said that "It is not wise to scan for malicious software and infected files from an infected operating system!". If I scan in an infected windows system will the infection spread more faster in all hard drive?[/quote]
Not in particular, there's a big chance that the anti-virus application is infected too, or being "fooled" by malicious software pretending being clean.
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Re: scan files and libre, microsoft office

Post by kost »

nomko wrote:
kost wrote: There is not proof I was thinking if there are this infection that running both in linux and windows.
You posted this remark: There are some rare infections that can run both linux and windows enviroment.



You said that "It is not wise to scan for malicious software and infected files from an infected operating system!". If I scan in an infected windows system will the infection spread more faster in all hard drive?
Not in particular, there's a big chance that the anti-virus application is infected too, or being "fooled" by malicious software pretending being clean.[/quote]

I saw there that maybe infection can run both in linux and windows http://askubuntu.com/questions/441458/c ... -to-ubuntu
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kost
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Re: scan files and libre, microsoft office

Post by kost »

kost wrote:
nomko wrote:
kost wrote: There is not proof I was thinking if there are this infection that running both in linux and windows.
You posted this remark: There are some rare infections that can run both linux and windows enviroment.



You said that "It is not wise to scan for malicious software and infected files from an infected operating system!". If I scan in an infected windows system will the infection spread more faster in all hard drive?
Not in particular, there's a big chance that the anti-virus application is infected too, or being "fooled" by malicious software pretending being clean.
I saw there that maybe infection can run both in linux and windows http://askubuntu.com/questions/441458/c ... -to-ubuntu
Linux for Ever :D
nomko

Re: scan files and libre, microsoft office

Post by nomko »

kost wrote: I saw there that maybe infection can run both in linux and windows http://askubuntu.com/questions/441458/c ... -to-ubuntu
No, You should read it better:
Threats don't transfer from one OS to another
Any thread for Windows does not have any effect at all in Linux since the architecture of Linux and Windows differs a lot. First of all the file system (ext3/etx4 for Linux and NTFS for Windows) secondly, Linux does not have the same folder structure and folder naming as Windows (Linux doesn't have a c:\Program Files directory for example or Documents and Settings folder). Linux works totally different than Windows. I think you getting a bit too paranoid here (no offence).

The only possibility for having Windows viruses on a Linux system is when you run Windows in a virtual machine and/or Wine. But even then it will only effect the Windows part not the Linux part. You should also be made aware that you can spread malicious software like viruses, trojans, malware and spyware (amongst others) with a Linux system. But again, that's only when you save infected files on a Linux system and sharing it with Windows users. And again, it still doesn't harm your Linux system at all.

So, like i said, it is better to store all files on an external device (memory stick, USB hard drive), use the Gparted livecd to erase all partitions on the hard disk of that laptop and boot with the Mint livedvd and install Mint. After installation, make sure you update your Mint setup first, install the proper graphic driver (can be found in the Additional driver menu) and install ClamAV and ClamTK (GUI for ClamAV) and scan that external device. Most likely some files aren't infected (which can be transferred to the laptop) and files who are infected can be placed in a quarantine folder of ClamAV or the infection can be removed to clear the file.

But i stay with my advise not scanning the files and folders with the infected Windows setup to avoid false positives from the anti-virus tool.

There are some viruses (or to say malicious software) for Linux, a part of them are just "lab viruses" never to be set out "in the wild" and others can't do much since Linux has a much better and secure rights management system than Windows. The chance of getting a virus for Linux... You probably hit the jackpot on a slotmachine in a casino in Las Vegas much quicker than getting such virus on your Linux system!

Since i'm using Linux in 2007, i started with Ubuntu 7.04, i never used an antivirus tool or anti spam tool of even a firewall. I played with such applications to find out it was totally unnecessary for me.
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Re: scan files and libre, microsoft office

Post by kost »

Thank you for the explanation.

I will scan the infected files with clamtk+av. The problem is that my friend will move or copy files in pc that is running windows. Do I need to scan with antimalware?
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nomko

Re: scan files and libre, microsoft office

Post by nomko »

kost wrote:Thank you for the explanation.[/quotew]
No problem!
kost wrote: The problem is that my friend will move or copy files in pc that is running windows.
Meaning moving/copying files from an infected system to a (hopefully) clean system? Better not to do this. The chances are big to infect the other system as well. Can he burn the files onto a DVD? Better to burn it on a DVD rather than moving/copying them to a clean system.
kost wrote: Do I need to scan with antimalware?
Scan with anti-malware, anti-spyware and anti-virus. Scan for everything.
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Re: scan files and libre, microsoft office

Post by kost »

Sorry the confusion. Lets try again.
You told me to install linux mint and then scan the external drive with the infected files with clamtk+av.
The problem is when my friend copy or move files to a pc that is running windows it will tranfer trojans,spyware etc that can run only in windows. So I have to scan the external device with the infected files not only with clantk + av but also with an antimalware. Is any antimalware program for linux?
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Pilosopong Tasyo
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Re: scan files and libre, microsoft office

Post by Pilosopong Tasyo »

kost wrote:Sorry the confusion. Lets try again.
kost wrote:First he wants to copy his files from windows in external device. After the installation of linux mint in his laptop he wants to move all his files from external device to his laptop. Do I need to scan the files before move the files to the linux enviroment?
If I may make a suggestion, making a slight change in your friend's procedure/logic will make the transfer less of a hassle, IMHO. The path of least resistance:
  1. Boot the Live CD/USB.
  2. Insert the backup medium, e.g. a USB flash drive (UFD).
  3. Use the file manager (Nemo, Caja, etc.) to copy the personal files (documents, pictures, et al.) from the hard drive to the backup medium. When you're done, unmount the backup medium and set aside.
  4. Install Mint on the computer. Reboot when done.
  5. Log in to the new installation.
  6. Plug back in the backup medium and copy back the personal files in the appropriate folders.
Done.

By following the procedure I enumerated above, your friend will bypass his Windows installation from the get-go and starts off with a guaranteed clean environment. Scanning the hard drive (let alone installing virus-scanning software) is no longer necessary, and your friend has exact control what files are being copied from the hard drive to the backup medium and vice-versa.

HTH.
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Re: scan files and libre, microsoft office

Post by kost »

Pilosopong Tasyo I can not understand how this way is safe.

When I boot from live cd and copy all the personal files files the infections will move to the back up media (external hard drive). Then after the clean installation I will move the personal files with the infections to the clean installation. So the infections will be in the new clean enviroment of linux. :(

Here "your friend will bypass his Windows installation from the get-go and starts off" you mean by passing the personal files from the beggining of the process until the end. Right?

How can be safe this way without scanning the files?

I think I found a safe solution.

1) Boot from live cd
2) Move the personal files to hard drive
3) Delete all partitions from hard drive with gparted live cd
4)Boot from again from live cd
5) Scan personal files from hard drive with clamtk+av
6) Then scan personal files with av+antimalware the external hard drive from pc that running windows
7) Boot from live cd and scan external hard drive with clamtk+av
8 ) Install linux mint and scan with clamtk+av the external hard drive from the new clean linux enviroment and move the personal files to the linux clean enviroment


Do you agree?
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Re: scan files and libre, microsoft office

Post by Pilosopong Tasyo »

kost wrote:Pilosopong Tasyo I can not understand how this way is safe.
...
Here "your friend will bypass his Windows installation from the get-go and starts off" you mean by passing the personal files from the beggining of the process until the end. Right?
Recall what nomko wrote in his earlier post:
nomko wrote:It is not wise to scan for malicious software and infected files from an infected operating system!
When you boot your computer into a Linux live environment, you are -- for all intents and purposes -- booting into a "clean room." Compare this with booting into your infected Windows install and trying to run your anti-malware software to get rid of an infection. It's next to useless since your Windows environment is already tainted in the first place.
kost wrote:When I boot from live cd and copy all the personal files files the infections will move to the back up media (external hard drive). Then after the clean installation I will move the personal files with the infections to the clean installation. So the infections will be in the new clean enviroment of linux.
...
How can be safe this way without scanning the files?
There are two types of file infections that I usually encounter:
  1. The malware creates/replaces/modifies system files or files unique to a Windows-only installation (most popular is the autorun.ini infection and variants).
  2. In the case of malware that targets Microsoft Office (MSO) documents, these insert malicious VBA code (again, VBA is Microsoft-centric) that gets executed when you open such infected files in MSO. These viruses also target the default template file (normal.dot) so merely creating a new MSO document guarantees infection. VBA macros won't get too far in LibreOffice (LO). MSO macros are pretty much incompatible with LO's implementation.
What do these imply? Well, most of the time, malware target executable binaries. You are going to transfer personal files, correct? Not Windows-specific binaries (*.EXE, *.COM, *.DLL files which are pretty much useless as far as Linux is concerned) or files that your friend didn't even create.

Data files (documents, music, pictures, et al.) don't open/run by themselves. You need applications to open these data files. And even if malware manage to insert executable code in your friend's personal files, applications normally won't even acknowledge these pieces of code as something to be executed on-the-fly. Your music player will just attempt to interpret the virus code as a wave form and will just sound off squacks, beeps, and noise when it reads off the data stream from the MP3 file. GIMP will just attempt to interpret the virus code embedded in the JPEG file as part of the picture itself when it renders it on screen. Of course, the exception here is macro code embedded in MSO files. However, this should be a non-issue since LO and MSO macros are incompatible. You'll have to shoot through hoops to make MSO macros run decently in LO.

So, what kind of infection are you referring to?
kost wrote:I think I found a safe solution.

1) Boot from live cd
2) Move the personal files to hard drive
3) Delete all partitions from hard drive with gparted live cd

4)Boot from again from live cd
5) Scan personal files from hard drive with clamtk+av
6) Then scan personal files with av+antimalware the external hard drive from pc that running windows
7) Boot from live cd and scan external hard drive with clamtk+av
8 ) Install linux mint and scan with clamtk+av the external hard drive from the new clean linux enviroment and move the personal files to the linux clean enviroment

Do you agree?
I'm afraid your new procedure is a bit vague, to say the least. You're going to move the personal files to a hard drive, and then delete the partitions? You pretty much nuked everything you moved. You're going to scan the personal files with the AV tools from a Windows computer -- the same Windows computer that is infected in the first place?

I find your booting the live CD several times a bit superflous. You can just boot into a live environment once, and do the (scanning,) transfer, partitioning, formatting, and installation in one go. Your external hard drive connects to the PC via USB anyway, so the OS will just treat it as if it's a UFD.

Or is your external hard drive a barebones drive that need the data and power cables to be directly plugged into the motherboard?

When it comes to procedures, you *need* to be clear and specific so readers don't get confused or get the wrong impression. Relevant details (or the lack of it) spell a huge difference between something done right, and disaster just waiting to happen.

Anyway, while erring on the side of caution is the preferred course of action, IMHO it's a little bit over the top and not really necessary, considering (a) you're transferring data files only and (b) you're going to do it under the clean environment of the live CD.

Now just because I said so doesn't mean it's gospel. I say these things based on personal experience. I've been using Linux full time since 2009 and also been running a small internet café about two years prior to making the switch from Windows to Linux. Seeing students insert their virus-infected UFDs in my computers on a regular basis is pretty much a non-issue for me. Some of them even ask me if I need to scan their UFDs or if my computers have anti-virus software installed. I tell them no need to since (a) Windows don't run on my machines, (b) Linux don't natively recognize Windows executables. I don't use WINE so any attempt to open an EXE or COM file on any of my machines, all they get is Archive Manager complaining some error in the file. Hence (c) I don't need AV software (Why should I? It's not my responsibility to clean their own mess). When they insert their UFDs, we can see the actual virus-infected files (autorun, VBS and DLL files with random names) listed in the file manager. These files normally get hidden in other cafés using infected Windows installations. When they open their MSO documents -- regardless if it contain macros or not, malicious or not -- no code gets executed. All they see in LO is a message notifying them that the document contains macros that LO doesn't recognize and won't execute. Document opens normally, no infection spreads out (there's none in the first place), and everyone is happy.

At the end of the day, take things with a grain of salt and carefully analyze and assess the opinions and advices we're offering you in this thread. Ultimately, the final decision on the course of action is up to you.

Also, have a look at this thread: Questions about Defragging or Antivirus? Look here first!
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kost
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Re: scan files and libre, microsoft office

Post by kost »

Thank you for the explanation.

What I want to do is to clean the files not only for linux enviroment but also for windows enviroment.

1)Boot from live cd
2) move all personal files to external hard drive
3) scan with clamtk+av
4) plug the external hard drive another pc with clean windows enviroment and scan with av+antimalware
5)Delete partitions with grparted and install linux mint
6) plug the external hard drive scan personal files with clamtk+av and move to clean linux enviroment


I want to scan in windows enviroment the personal files because maybe in the future can copy file in usb and transfer in windows enviroment.So the personal files I want to be clean also for
windows enviroment.

Is it safe?
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Re: scan files and libre, microsoft office

Post by Pilosopong Tasyo »

That's better. You should be fine. :D
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Re: scan files and libre, microsoft office

Post by kost »

Pilosopong Tasyo wrote:That's better. You should be fine. :D
This is better solution than yours? or its the same?
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