How to be save from Vampires? 

If you’re in Transylvania, if you walk into the street just wear a cross necklace or put white garlic on your fragrance. Count Dracula and his minions can’t go into a house if they were not invited into one’s house. So, as long as you keep away from inviting them, they can’t go in.

How to be save from worms?

If you’re using Ubuntu, just stay away from unofficial repositories.  Don’t worry about worm, trojans, etc! Every packages in Debian and its derivative (including Ubuntu) must get signed. The signer must be eligible to do so. Official repositories get maintain by such people.

Wait, what? There is such vampires worms?

No, there isn’t any worms in Ubuntu, not like the one works in other OS ™. With the UNIX-like architecture, GNU/Linux operating system is protected by default with kernel provisioning. With the years of recommendation of using user-space level programming than kernel level, which the other OS ™ version 7 now also use, applications can’t go into kernel mode and override things without provision.

One practice that we are practicing for years is avoiding using “root” account. There are projects like

sudo

to do even fantastic job: erasing root’s password. Every application runs as regular user. That’s why there such a special user available with special interest like the “www-data” user for web applications (Apache Webserver, lighttpd, nginx). There is also groups that are able to do the specific job. Special nodes (those in “/dev”) have group access limit so that only few users that belong to that group can access it.

BUT, there is a possibility of an application patched with malicious code from malicious contributor for error doing (like making your computer as a Botnet). The example is the now-deceased free screensaver from gnome-look.org. Luckily, it is a community driven, so the ill-work has been detected and eradicated.

Err… in the human language meaning? 

Just do things normally.