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Removing viruses from your home directory

Home directoy infected with a virus? This article explains how to remove it.

Norsk versjon - Fjerne virus fra ditt hjemmeområde

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Removing viruses

NTNU IT regularly scans all files in all network directories (including home directories) for viruses. The entire process is automated through a regularly scheduled program, meaning that there is no one who can see your personal files, or who the owner is of certain files. When the program detects infected files, the owner will receive an email with information about the infection (alternatively, an email list if it applies to shared network directories), and with a request to disinfect the files before continuing to use the directory.

The program will also remove all read- and write permissions on infected files in home directories (not shared network directories), to prevent you from accidentally spreading the virus by opening the infected files. This results in your being unable to read (open) and delete the files in Windows.

What do you do?

  1. First, update the antivirus definitions for your antivirus software. If you do not have antivirus software installed read more here.
  2. Log in to your home directory using SSH. Note: you can not use the Mindterm client (browser-based) to connect for this purpose. Use for example Putty.
  3. If you want to delete the files, navigate to the folder and use the command "rm filename.doc"
  4. If you want to disinfect the files, use the command "chmod u+rw filnavn" to alter the permissions of the file. Then, disinfect the files by connecting to your home directory, and use your antivirus software to scan and disinfect the directory.

If you want to delete the files

The easiest option if you just want to remove the files is deletion. Simply right-click on the relevant file and select Delete (Slett). In Unix, give the following command: "rm filename.doc"

  • Put the file name in quotation marks if the file name contains spaces (f.ex: "My document.doc"), like this: rm "My document.doc"
  • You will be prompted: rm: remove write-protected file `filename.doc'?
  • Enter y (for Yes), and the file will be deleted.

If you want to keep the files

If you want to keep the files, you must somehow disinfect them before you start using them again, or the process will start over, and you will soon receive another email from NTNU IT.

First, you must alter your permissions for the relevant files. The command chmod does this.

  • A typical example is: chmod u+rw filename.doc
  • Again,if the file name contains spaces (f.ex: "My document.doc"), put it in quotation marks like this: chmod u+rw "My document.doc"

Now you can use an antivirus software to disinfect the files!

Disinfecting files

The process of disinfecting files depends on the antivirus software you use. If you are on a computer lab, on NTNU's wireless network, or connect to your home directory from home, you will be using the antivirus software installed on your local computer.

Antivirus is installed on most of the computers in general NTNU. Start file explorer, and connect to the home directory if you haven't already. Then, right click the folder you want to scan, and select Scan Folder for Viruses in the menu. The software will hopefully find the virus, and automatically disinfect it or ask you what you would like to do with the infected file.

Contact

Orakel Support Services can help if you encounter difficulties. If you are an NTNU employee, consult your local IT Support.