Unit 4 - Network security & system software

• comes from 2 words: malicious software • executable programs that run on a computer

• Viruses • Worms • Trojans • Ransomware

Computer viruses infect computers by: - replicating their code in other programs - infecting other computers - harming the computer by deleting, corrupting or modifying files

• replicates itself in order to spread to other computers • may cause no damage to the attacked computers • slow down networks and computers

• a program, game or cracked file that user wants • they have a negative programs code which causes damage, takes control, or provides access to the computer

Software which: - holds a computer hostage by locking or encrypting access to it - if the data is encrypted, not even a cyber security professional will be able to recover the data unless backups are available. - the access will only be restored if the ransom is paid.

• unpatched software • out-of-date anti-malware

if software updates and security updates are not installed then the software will be vulnerable

if software, such as antivirus software, isn’t regularly updated then it won’t be able to detect the latest viruses

Social engineering is the ability to obtain confidential information by asking for it.

Shoulder surfing is the ability to get information or passwords by observing as someone types them in.

Phishing is a type of social engineering technique, emails, texts or phone calls are sent to users commonly pretending to be from a bank or website.

• Greeting: greeting is not personalised • The sender’s address is often a variation on a genuine address • Forged link: The link looks genuine, but it may not link to the website given. • Poor spelling and grammar • Request for personal information: Genuine organisations never do this • Sense of urgency: Criminals try to persuade you that something bad will happen if you don’t act fast

In a denial of service attack, a hacker will use or infect a computer so that: - it sends as many requests to the server as it can (known as a flood) - the server can’t respond fast enough so slows down or goes offline

many computers are used to send the requests

allows the attacker to intercept communications between the user and server and: - eavesdrop to find passwords and personal information - add different information to a web page or other communication such as email

• losing mobile phone can lead to loss of all data in it • malware can allow malicious users to acces device • some apps are malicious and lead to fraudelent charges

• use strong password • encrypt data • dont follow links in sus emails • dont install apps without researching them • delete all info on phone before discarding

In a brute force attack, a hacker will try every combination of password until the correct password is found.

uses web forms to add SQL instructions to a query that cause data loss or the revealing of personal information

The practice of deliberately trying to find security holes in your own systems.

testing to: - identify the targets of potential attacks - identify possible entry points - attempt to break in - report back the findings

Anti-malware software will detect malware such as viruses, worms, trojans, and spyware

• When a virus or new malware is detected it is sent to the anti-virus company. • malware is verifies, then a signiture of malware is crated • signiture is added to virus database and tell computers to run an update