Huge thanks to all for the replies
pdecker
I have read of virus that can detect they are in a virtual machine
ouch!
Good point about shared clipboard.
That is my main concern to do the backup
Paul
If the document is stored on a drive windows can see then its posible to infect the windows portion
- It is stored in a pendrive to be mounted in Linux as Host
- It must be shared to the Guest through Shared Folders
- The file is opened
- The content should be copy and paste (here enters the Shared Clipboard) to the host
Is not possible due security reasons to create a new file in the guest itself to be accessed later through the Shared Folder from the Host.
Simple answer would be if you suspect a file or source delete it or dont introduce it to your system. Better safe than sorry.
Agree but the file must be opened.
Go back to the original supplier, inform them of your suspicion and get them to retest and re submit
The scenario for a better understanding is as follows:
- A student is the owner of a PDF file
- The student must do his course by 2 hrs in the laboratory
- The laboratory and any machine is accessed by more of 100 students from many grades
- So the PC even if is “frozen” sometimes is formatted by virus. Of course the antivirus failed.
- The PDF file arrives to the PC Desktop of the laboratory through either a pendrive or downloaded by email
- The PDF file is opened to read and to be edited … finally saved …
Xander
There is malware which is able to infect both Windows and Linux. It’s rare, though as most are developed to assume Windows
Agree
That being said, I wouldn’t take my chances and contact the supplier of the PDF to inform them you suspect it’s infected with malware.
As the previous list
You could also use clamav to check the PDF for infections.
It is going to be done too
I would never use Adobe Reader to open a PDF (because it’s bloatware and does some stuff I wouldn’t allow such software to do).
Ok, but is need it:
- Read comments
- See the Paragraphs highlight in colors
It is the current content and structure of the PDF files
Using something like SumatraPDF is preferable. It’s small, fast, and is focused on the features you actually need. Besides: it’s open source, so you can go and audit it, if you want.
Thanks for the suggestion. Please let me know if is possible:
- Create/Edit/Read/Delete comments
- Put Paragraphs with highlight in colors (and remove too)
Finally: on what basis do you think it’s infected with malware?
Based on the list mentioned above
Laszlo
I don’t think it’s possible. As cameraman I visited a dozen times the Hacktivity in Budapest (I worked there, but meanwhile also attended silently 
). This is a cyber security conference. I remember a (white hat) hacker in a presentation mentioned he uses virtual machines to do some testing with malwares, as it is a controlled and closed environment.
Interesting and valuable feedback but:
- Should we assume their VMs run in a Host that can be formatted and reinstalled anytime?
That changes the situation, as the malware running in the VM can reach data on the host (I think this is what @callpaul.eu also mentioned).
If he is correct then I must connect and mount the pendrive in the Guest. It to avoid the Shared Folders approach. But is mandatory first to put it in the host. Anyway the PDF file is not going to be opened in the host
So it can write there, possibly infect other pdf files, but it cannot get outside of that shared folder. I mean, you give the VM /home/jordan/sharedfolder with write permissions, the malware in VM could possibly infect any file that resides in that folder or its subfolders. But I don’t see a way the VM could infect anything in /home/jordan/documents for example.
But the problem would be if is later from the host is accessed the /home/jordan/sharedfolder directory. I mean the Guest had created/infected any file from there and later is accessed by the Host