- [Craig] In this video, we look at the following cybersecurity threat, malware
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So the first thing to understand is that malware is actually an umbrella term
used to refer to a variety of forms of hostile or intrusive software.
It covers a vast range of sub-categories,
but there are five that you need to know about for your exam,
and that's viruses, trojans, worms, ransomware and keyloggers.
So the first, and typically the one that most people are aware of, is the computer virus.
This is simply a piece of code which is capable of copying itself,
and typically, it has a detrimental effect such as corrupting the system or destroying data.
Computer viruses can be introduced to computer networks and systems accidentally
or sometimes on purpose with malicious intent.
The next category are trojans.
Now this is a program that appears completely harmless but is in fact malicious.
A lot of people receive trojans when they download software, games, patches
or other data off the internet from unreliable sources.
Always make sure you're getting downloads from trusted vendors.
It may be tempting to, for example, download a game from an untrusted site,
possibly because they're offering it for free.
You download the game and, indeed, the game installs on your PC.
However, along with your download as you install it comes a trojan,
which silently installs itself in the background and sits on your device.
Unbeknownst to you,
the trojan has now installed what is known as a back door into your computer system,
a little program that allows an external hacker to then bypass your computer security.
This could be sat on your system for weeks, months or even years
without you realising that someone else has access to your computer system
and is monitoring your usage,
your passwords and your internet traffic.
So a worm is similar to a computer virus in design
and it's often considered a subclass of computer virus.
However, the difference here is a worm can spread without the need for human interaction.
It has the ability to self-replicate.
In the example below, the worm has created thousands of copies of itself
and is automatically sending itself out to everyone in your address book via email.
This means it can easily spread through lack of knowledge and awareness.
So ransomware is a form of malware which encrypts a victim's files.
The attacker then typically demands a ransom or a payment from the victim
to restore access to the data.
Users are shown instructions for how to pay a fee to get the decryption key.
The cost can range from a few hundred dollars to thousands,
and it's often payable only in Bitcoins
because these are typically much harder to track and trace.
WannaCry infected more than 300,000 computers with ransomware across 150 countries in 2017
and for a number of days crippled parts of the NHS in the United Kingdom.
It was called, at the time,
the biggest ransomware outbreak in history.
Finally, we have to think about keyloggers.
This is software that obtains covert information about another's computer activities
by silently monitoring and recording their keystrokes.
Keylogger software often ends up being installed via a trojan.
The information gained by the keylogger is then transmitted covertly back to the original attacker.
If you think about all the daily activities you do using your keyboard,
you can realise the potential danger of a keylogger.
It could be monitoring your internet surfing habits and the sites you visit,
recording email addresses, passwords, credit card numbers and more.
So let's just recap.
Malware is an umbrella term used to refer to a variety of forms of hostile or intrusive software.
The different types you need to know about is shown on the screen.
Pause the video and take some summary notes.
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