- [Craig] In this sequence of videos, we explore network security and a variety of threats to computers and servers today.
What are the forms of attack, what is the threat,
and how can you identify and prevent vulnerabilities?
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In this specific video, we look at the threat that each attack poses to the network
and the effect that it can have on individuals, the system and businesses.
So, first of all, malware.
In this situation, files may be deleted, they can become corrupt or even encrypted.
The computers may end up crashing, rebooting spontaneously or slowing down without any logical or reasonable explanation.
When a worm infects a computer, the internet connection may become slow as the worm searches online for other computers to infect.
However, the worst symptoms of malware are often the ones that you do not see.
Malware can be designed to simply record the keys that you press on your keyboard.
For example, creating a text log that your computer then sends to a hacker periodically.
The hacker then scans the text log looking for passwords they can use to access your email or bank accounts.
It's worth noting that in a network situation, if a client becomes infected with malware,
this is easily passed to the server and then to all other clients connected.
Infections are able, therefore, to spread very quickly on networks.
If you are a victim of phishing, a hacker can withdraw money or purchase merchandise or services.
They can, say, open new bank accounts or credit card accounts in the victim's name.
And they can use the new account to cash illegitimate cheques or purchase merchandise.
They can use the information to gain access to high-value corporate data.
And financial services can end up blacklisting institutions, resulting in reputation damage.
With a brute-force attack, the hacker is trying to access corporate systems,
potentially to steal data and gain access to sensitive information.
When hit by a denial-of-service attack, a company can lose revenue.
This is because server downtime leads to a loss in profits.
Based on industry surveys, the average cost of downtime is over four-thousand pounds per minute.
It can also result in productivity loss.
When critical network systems are shut down, your workforce's productivity comes to a halt.
And of course, it can lead to reputation damage.
Your brand can suffer if customers can't access your site or become casualties of a data breach themselves.
With data interception, users and passwords are compromised, resulting in unauthorised access to systems.
This can lead to disclosure and theft of corporate data.
The photo shown here is an example of a packet-sniffer,
a device that can actually listen to the data that's being transferred between two points on the network.
And by sniffing that data, the hacker is able to access usernames and passwords,
which they can then use to log into the system in what seems like a legitimate way.
With SQL injection hacks, the contents of the database can be output, revealing data that otherwise would have been hidden.
The data in the database can be amended or deleted,
and new rogue records and entries can be added to the database as well.
Many system vulnerabilities are caused simply by people being careless.
We refer to these as people being the weak point in the system.
Here are some simple examples.
People not installing operating system updates.
Not keeping anti-malware software up-to-date.
Not locking doors to computer rooms or not logging off.
Leaving printouts on desks with sensitive information.
Writing passwords down on sticky notes and then attaching them to computers.
Sharing passwords with colleagues.
Losing memory sticks and laptops.
Not applying security to wireless networks and not encrypting data.
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