[SOLVED] Do I have a virus??

briandc · 09-11-2011, 03:39 AM

Hi everyone,
Here's the situation:
I recently installed PCLinuxOS LXDE 06.11.
I use this pc at home, but a Windows XP pc in the office.

I created a database with OpenOffice Calc, and it contains hyperlinks to files that contain jpg pics. These pics are organized into folders with codes: M001, M002, M003, etc.

I use a usb pen drive to save modifications to the calc sheet and relative jpg folders and save them all at home.

But yesterday, after installing LXDE at home and saving the database w/folders, when I opened the database and clicked on the hyperlinks, they wouldn't open. I finally realized why: all of the related folders (and some pics) had been changed to *lower case* , such as m001 and m002 rather than M001 and M002. Obviously, the hyperlink therefore didn't see the folder paths.

Do I have a virus? (I can't think of how that is possible, as the installation is new..)
Or is there a bug somewhere that changed the folders to lower case?

Thanks to everyone for the input..

Brian

ButterflyMelissa · 09-11-2011, 03:59 AM

Quote:

Do I have a virus?

No, you dont. May I expand on this?

For starters, and this is not a newbe observation you did, Linux is CaseSensitive. A hyperlink to the original storage will have been broken, so...yeah. A hyperlink to the Net, well, that'll stil work.

Okay, on to the anatomy of a virus.
A virus is a program. Unless "installed" to start along with the rest, a virus needs to get a pulse to start. Just like any program. In the "abomination", it's simple, any program can access any part of the system's disk. And, hence "install" itself. Linux has a barrier: your system rights. And these forbid you (unless you've broken these down...I hope not) to alter anything outside your home folder.
Assuming a virus, therefore, would have been on the USB stick, the mechanism to start it up is not there. In Linux simply being a program (script or otherwise) and simply requesting execution does not at all guarantee Linux will simply start up the program. The possibility to anchor itself in the system is non-existent due to your rights, it will "borrow" these from you, or whatever account it lands into. As does anything in your folder (programs, scripts,...) the mechanism to wreack havoc is non-existent, as havoc means alterring the system...

Believe me, a virus is the least of your worries in Linux

Happy Linuxin' and welcome to the forum!!

Thor

Edit : demo of "to run or not to run, that's the question"

This is a little PERL script, open gedit and paste this in there, save as rundemo.pl

Quote:

#!/usr/bin/perl

print "this thing can run...\n";

(assuming PERL is installed)

...now, enter the console and enter that name...chances are you'll get a

Quote:

permission denied

or somthing like that, now, still in the console, enter this:

Quote:

chmod +x rundemo.pl

and now try to run it...
See? If a virus does not have the run flags up, Linux will not even take a sniff at it...

colucix · 09-11-2011, 04:12 AM

As Thor already explained it's not a virus. This is the behavior of VFAT filesystems. Since they don't distinguish between upper and lowercase in file names, it's up to the mount command to decide how to display them. From the mount man page:

Code:

shortname={lower|win95|winnt|mixed}

      Defines the behaviour for creation and display of filenames which fit into 8.3 characters. If a long name for a file
      exists, it will always be preferred display. There are four modes: :

      lower  Force the short name to lower case upon display; store a long name when the short name is not all upper case.
      This mode is the default.

      win95  Force the short name to upper case upon display; store a long name when the short name is not all upper case.

      winnt  Display the shortname as is; store a long name when the short name is not all lower case or all upper case.

      mixed  Display the short name as is; store a long name when the short name is not all upper case.

As you can see the lower mode is the default. You can change that by setting the mount option shortname=winnt. Depending on how the filesystem is mounted (manually or automatically) you have to add this option somewhere.

TobiSGD · 09-11-2011, 04:13 AM

Deleted, colucix explained it way better than me.

briandc · 09-11-2011, 05:11 AM

Hi guys ( and thanks for the quick responses!),

It's nice to hear confirmation that it isn't a virus. I understand the problem is with FAT, although I used the same stick and procedure when I had Xubuntu installed, with no problem. It acted like Windows. Apparently, PCLinuxOS makes a distinction by default. What's strange (and the reason for fear of something malicious) is that not all the jpg files in the folders were changed to lower case! In some folders, all were changed. In other folders, only some were changed. In others, none were changed.

So..
as I'm new to Linux, can someone walk me through the process to make my system act like Windows for this issue? I'll check in again here in a few hours..

Thanks guys. Hopefully someday I'll be able to help others as well!

Brian

ButterflyMelissa · 09-11-2011, 09:51 AM

Quote:

as I'm new to Linux, can someone walk me through the process to make my system act like Windows for this issue? I'll check in again here in a few hours..

Well...not really LIKE ... the "thing" ... but, we can go further than that.

Xubuntu uses XFCE...and, PCLinux has its own rules. All I can say is : welcome to Linux. These differences are not bugs, but features. I for one welcome the fact that my system cannot by default "slurp" up all that's on a stick.

Linux makes differences between upper and lower case, it's the shell (XFCE, Gnome, E17 and the like) that try to "think with you" in such matters...

Maybe, this is the first (and best) experience in Linux: choose a distro that fits YOUR needs. And consider the desktop as well...

By the way, Linux is not windows...and for some good reasons...

Quote:

Thanks guys. Hopefully someday I'll be able to help others as well!

Ooooh, dont you worry...that day will come!

Thor

briandc · 09-11-2011, 11:42 AM

Ok, I'm back.
So, should I use the "shortname=" command somewhere? How do I find out where to put it??

I've used line commands in the past, and I even understand the reasoning behind much of what I've done. But since I'm not a programmer, I think there's still a lot I need to learn about how to use them well..

At any rate, for the moment, I don't have a lot of time to fish around for answers, unfortunately. I could install a different OS, but I really like what I'm seeing in this current one, and if I can learn to change the default for my files, that would be great. (I also would like to change the file association for the jpg files, so that they always open with Ristretto; unfortunately, I can't find any GUI-type apps that can change this for me, either...)

So, can anyone help me resolve this issue? (BTW, I've tried to register at the PCLinuxOS website to use their forum, but my email addresses are considered spam (all 3!) and no one has helped me register there, either!

Brian

briandc · 09-11-2011, 12:00 PM

Just a sidenote:

I have a third pc, a bit older, from when XP came out in 2001; I installed SwiftLinux (Minnesota version) on this one, and not only is it fast... it also reads the files as they should be (as M001, M002, etc)!!!

So I can confirm that this must be a PCLinuxOS issue. --I just hope someone here can help me solve it!

Brian

chrism01 · 09-11-2011, 08:51 PM

Can't help with PCLOS, but this is a good Linux tutorial http://rute.2038bug.com/index.html.gz

briandc · 09-12-2011, 07:05 AM

Quote:

Originally Posted by chrism01

Can't help with PCLOS, but this is a good Linux tutorial http://rute.2038bug.com/index.html.gz

Thanks Chris!
This looks really good for starters. Of the two computers with PCLOS installed, last night I replaced it was Mageia KDE 1.0, which does everything and then some!

Still, the other pc looks so nice with PCLOS, and for my own "educational" benefit, I'm going to see if I can learn to change things at the command line so that it's just right!

Thanks to all here,
brian

DJ Shaji · 09-14-2011, 11:22 AM

Just a side note, even though the thread is solved ... a windows "virus" won't work on Linux, at least not without effort on the part of the user (installing wine .. libs )

briandc · 09-15-2011, 07:13 AM

Quote:

Originally Posted by DJ Shaji

Just a side note, even though the thread is solved ... a windows "virus" won't work on Linux, at least not without effort on the part of the user (installing wine .. libs )

Hi DJ,

Interesting..
So, is Wine at risk of allowing viruses in? If so, how? because it allows .exe files to be opened?

Just wondering..

Thanks
brian

DJ Shaji · 09-15-2011, 08:57 AM

Wine is essentially a way to run windows programs on other operating systems. A "virus" is pretty much a program; so, depending on what it is supposed to do, it may or may not cause damage to any platform it runs on. In my opinion, more "complex" viruses out there may not be a threat to wine, at least some damage can possibly be done, as far as file system and network access is concerned.

Also, I would imagine somebody would have to acquire and run a "virus" by hand to execute it; it would be pretty difficult - but possible - for a virus to "infect" a wine installation. I don't think it has ever happened, though.

Finally, it would be unlikely for such an "infection" to seriously damage a linux system; all somebody may risk is deletion of stuff in their home directory (or whatever wine sees as "C:").