Revision as of 14:05, 25 July 2015

This page contains some basic security measures specifically for people getting started with linux. Knowing your way around a bit on the kinky linux command-line is required for easily doing these steps. If you run into trouble, find us on IRC.

Setting up root mail

Installing intrusion detection

Turning camera off

Hackers gain access to their victims’ computers with remote-access Trojans (RATs) – malware that gives an intruder administrative control over its targeted computers, including, in this case, the ability to remotely control webcams. It’s an invisibly-installed malware program spread via email attachment or by tricking victims into visiting a booby-trapped site.

Tape the camera. It may even be possible to turn it off in BIOS (depending on your version). Better yet, if you know what driver module is controlling the webcam, you can disable the driver with modprobe -r. Check with:

$ lsmod | grep "uvc"

If stuff like this appears, your webcam device uses an uvc driver http://www.ideasonboard.org/uvc/:

uvcvideo               79005  0 
videobuf2_vmalloc      12816  1 uvcvideo
videobuf2_core         47787  1 uvcvideo
videodev              126451  3 uvcvideo,v4l2_common,videobuf2_core
media                  18305  2 uvcvideo,videodev
usbcore               195340  7 uvcvideo,ums_realtek,usb_storage,ehci_hcd,ehci_pci,usbhid,xhci_hcd

To disable the cam:

$ sudo modprobe -r uvcvideo

To enable the cam:

$ sudo modprobe uvcvideo

If not an uvcvideo driver, try $ sudo lsmod | grep "video" and use the modinfo command to find out more about a particular module:

$ sudo modinfo [modulename]

Then replace the "uvcvideo" in the above modprobe command with the name of your driver module.

To disable the webcam at boot (if file not exists, create it):

$ sudo geany /etc/modprobe.d/blacklist.conf

At bottom of the file add this line: blacklist uvcvideo (or the name of your driver instead of "uvcvideo").

Save the file and reboot. Your webcam is no longer functioning.

Turning microphone off

Open the alsa control panel for muting the microphone:

$ sudo alsamixer

You can also use the same modprobe enabling/disabling method as used above for webcam. This page may be helpful for finding your driver module: http://alsa.opensrc.org/ALSA_modules.

Managing passwords

Using a password manager allows you to load passwords in your clipboard, making it hard to catch it with a keylogger (just in case). And all good password managers allow you to generate passwords, making the passwords independent from your personal preferences and harder to crack. One of the easiest password managers is a GUI tool called keepassx:

$ sudo apt-get install keepassx

It will appear in your menu. A "first steps" tutorial can be found here http://keepass.info/help/base/firststeps.html

Recommendations:

• Keep the database on a removable medium like an encrypted USB stick.
• Use a second encrypted stick to keep a backup of that database on.
• For added security, set up the database to use a password as well as a keyfile.
• Try to always close off the application. It uses a lockfile to prevent access by other processes. Quitting the application removes it. If not, and whenever you get a message that you cannot open your database, check on the USB in the directory where the database resides that there isn't a lockfile blocking access. If there is a lockfile while the database is not open for you, just delete the lockfile.
• On rare occasions a database is truly corrupted. That backup on that other stick, phew. :D

If you want to try your hand at cracking your own (current and new) passwords, try one of these http://sectools.org/tag/pass-audit/

Using a firewall

With a firewall, you can:

• Log hosts scanning services that aren't running
• Limit the services that programs can connect to
• Segregating the network into trust segments (LAN, DMZ, and Internet)
• Redirecting ports to the hosts providing the service (NAT).

If you have a single machine only the first two would be of interest. These are also the two that are most likely to cause issues for a beginning user.

In mint and ubuntu, a firewall is installed (the icon is a brick wall), but is disabled by default. Usually it's better to turn it on. Especially on mobile devices like laptops, which sometimes connect to other networks than your own. The firewall is called Uncomplicated Firewall (ufw), and can be operated from the terminal. Menu > Accessories > Terminal

$ sudo ufw enable

Type your password when prompted; this will remain entirely invisible, not even asterisks will show, which is normal. Uncomplicated Firewall (ufw) has a sensible set of default settings (profile), which are fine for the vast majority of home users. So unless you have special wishes: you're done!

You can check the status of the firewall with this command:

$ sudo ufw status verbose

If you wish, you can install a GUI frontend to ufw, called gufw:

$ sudo apt-get install gufw

Safer browsing

   ...

Encryption

Further hardening of armour

Resources

Related

• Installing linux
• Linux applications
• Kinky linux command-line
• Object encryption on linux
• Anonymising your traffic with linux
• Clean up all the things
• Shell scripting