Network Hardening Measures - Edexcel iGCSE Computer Science

Testing

Penetration Testing

Companies are increasingly paying white-hat hackers to try to break into their networks.

Often the best way to find out if your system is secure and to expose any system vulnerabilities, is to employ a white hat hacker to try and break into the system.

They deploy a number of different tools and techniques to try and access the system. Once a vulnerability has been exposed the system can be patched to fix the problem or the appropriate policy be put in place.

Some companies offer hack bounties to hackers. If you can hack their system and prove it you are rewarded with a hack bounty, which can often be tens of thousands of pounds.

Hack Bounty Website

Forensics

Network Forensics

If an organisation’s network has been hacked, it is important to learn how and where the breach occurred so that systems can be hardened

If an attacker is successful in accessing a network or computer, Network Forensics can be used to find out:

Who the attacker is (through their IP address or other information)
How they gained access to the system, so the vulnerability can be fixed
What information they accessed
What their motivates were.

This can be achieved by looking at access logs, using specialist forensic technologies.

Policies

Network Policies

Secure network policies can be highly effective in reducing successful attacks and mitigating the effects of a successful attack.

Good network policies include:

Forcing users to change their passwords on a regular basis
Forcing users to pick a strong password
Restricting user access only to the files / folders they need access to (see User Access Levels)
Regularly monitoring access to check for suspicious activity

Antimalware

Anti-malware Software

Malware comes in many forms and forms a whole spectrum of threats

Malware is software that contains features or extra software that either compromises a system or in some way impairs the user’s experience.

Examples include:

Installing browser add-ons that redirect web traffic via adverts.
Installing extra software that turns your computer into a bit-coin miner, costly you money in electricity
Installing software that allows governments or organisations to spy on you, tracking you browsing habits.

Anti-malware detects, disables or removes harmful software.

Firewalls

Any computer or device connected to the internet is vulnerable to unauthorised access. In order to reduce the number of attacks a firewall is used to detect incoming and outgoing traffic and destroy suspicious packets that don’t meet the firewall’s rules.

These rules often:

Block traffic from known bad IP addresses (or block and entire range of addresses that originate from certain areas)
Block access to certain ports.

UAL

User Access Levels

An effective way of preventing and containing threats to networks is through the use of User Access Levels.

Each user is given access rights(permissions) to the areas of the network.

Each right is limited to:

read (view files)
write(edit files)
full control(delete/add files)

This means that if an account is compromised, only certain areas and resources are exposed.

Passwords

Enforcing strong passwords using network policies are an effective way of reducing the possibility of successful network attacks.

Strong passwords

Mixture of lower and upper case letters.
Include a number
Include the use of characters e.g “£$%^&
Make sure that standard words are not used on their own. (dog)
Make sure the password is long enough to prevent a brute force attack.
Change passwords regularly
Use different passwords for different accounts
Don’t use easy to guess passwords (password123)

Limited Login attempts

Users are limited to a certain number of login attempts, after which their access is suspended for a period of time
Especially useful against brute force attacks

Biometric Password

Proxy

Proxy Servers

A piece of network hardware that hides a devices real location and IP Address.

When communicating across the network data is first send via the proxy server where the sender’s IP address is replaced by the proxy server’s IP address before being send onto the destination server. This allows a certain amount of anonymity and security.