Computer security in English, Slide di Informatica

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Protecting computers

Flipped classroom activity on Computer threats: each couple prepares a set of slides on a given topic and presents its content to the rest of the class

Computer threats: research task - Usberti, Esposito,

Angetti

Definition : Malware (short for malicious software) refers to programs designed to compromise computer functions, steal data, bypass access controls, or damage hardware

History : The term was coined by Yisrael Radai in 1990, though the first example, the Creeper virus , dates back to 1971

Main Categories: Malicious programs: Designed to damage data or hardware

Crimeware: Used to steal money or sensitive information

Mobile malware: Specifically targets mobile devices

Network threats: Attacks aimed at intercepting or affecting data transmission

Backdoors: These find secret ways into a system to provide a connection for hackers or other malware to enter

Rogue Security: Deceptive programs that pretend to be antivirus software to remove fake infections, while actually disabling the computer's real security

Adware: Also known as advertising-supported software, it delivers unwanted adverts While often used to recover development costs, it can degrade system performance or track user information without consent

Threats

Spreading Malware: Authors use USB drives, internet downloads, or emails disguised as legitimate messages containing malicious links or attachments

Spam: Junk mail is a primary medium for spreading malware, consuming user time and network bandwidth

Bugs: A bug is a flaw in code due to human error. These security flaws are dangerous because they allow hackers to bypass authentication, steal data, and compromise host computers

Delivery Methods and System Vulnerabilities

Crimeware to steal data

● Spywares : are designed to spy on the user’s activities without their knowledge in order to steal sensitive informations such as passwords, research informations etc. There are different types of spywares: ○ Keyloggers: record everything is being typed on the keyboard ○ Tracking cookies: track the online navigation habits of the device ○ Adwares: bomb the device with ads

● Phishing : is a type of online scam. One type of phishing can be an email that can lead to reveal the password of an account. It can be mass-mailed to a big amount of users or sent only to specific people with certain characteristics

The main types to crimewares to steal data are:

Crimeware to steal data

● Rootkits : are designed to gain remote control of a person’s computer without being detected by him or the antivirus software. They can execute files remotely, steal data, modify the system configuration or install other types of malware.

● Trojan horses: trojans disguise themselves as normal files or programs and trick users into installing malware. They can give remote access to the infected computer in order to steal data or modify files

Computer threats: research task (Rizzo, Predieri, Izem)

What's DOS? (pp.269)

What’s DOS/DDOS? pp.

DOS (Denial of Service) is a type of attack where a malicious actor floods a target network or system with a large amount of packets.

If the system is not protected and is unable to cut off the attacker, the packets will cause its network interfaces to go down under the immense load and the server will no longer be able to respond to legitimate requests, effectively halting the service for as long as the attack goes on.

This type of attack is easily preventable by blocking suspicious requests and introducing rate limits and load balancing.

What’s DDOS instead?

DDoS (Distributed Denial of Service) is an attack that follows the same principle of DoS but in this case the attacker uses a botnet, which is a large amount of infected devices (Zombies), ranging from mobile phones and computers to appliances and smart lightbulbs to send the packets from a lot of different sources making any effort to identify the attacker and block them useless.

This attack is still preventable through other security mesures but it is still extremely dangerous and widely used today.

Computer threats: research task (Granelli,Djebali,Di Salvatore)

Focus on network malwares (definition, objectives, main types): pp.

Network malware is any software intentionally designed to disrupt, damage, gain unauthorized access to, or steal information from different networks.

Intercepting data packets

Some attacks work by intercepting data packets. Their main purpose is to compromise the confidentiality of data as it travels across a network.

There are 2 main types of threats that intercept data as it travels through the network, like:

● Packet sniffing: sniffing a network means capturing and analyzing all the network traffic. It’s used by technicians in order to monitor the network, but it can also be used by intruders. ● Port stealing : in this kind of attack, the intruder steals all the packets that are directed to a specific port by tricking the switch into believing that his port is the correct destination of the data.

Accessing sensitive data

In some case the intention of the network attack is to access

sensitive data:

Spoofing : A trick where message is sent from an unknown

source but pretends to be a known source. The attacker

makes the bad message look like it comes from a trusted

machine by faking the IP address. For example, spoofed

emails might ask the receiver to send an account number.

The attacker then uses this number to steal their information.

Unauthorized access : Getting information on a user’s

computer without permission. This happens when someone

gets access by using another person’s account or by guessing

the username or password

Computer threats: research task (llotti, uzzi, oshka)

What is a firewall

A firewall is hardware or software that

monitors and controls network traffic between

trusted and untrusted zones, enforcing rules

based on IPs, ports, protocols, applications,

users, or time. Types include packet-filtering,

stateful, proxy, and next‑generation (NGFW).

Deployments: perimeter, host-based, and

cloud.

Computer threats: research task (Coppellotti,

Lamanuzzi,Broshka)

Antivirus software

Antivirus software is a type of application used for scanning and removing viruses from computer. Most programs include both automatic and manual scanning, while others offer free online scanning.

The automatic scan may check files downloaded from the Internet, storage devices inserted into the computer, and the entire hard drive on a regular basis.

The manual scan option allows the user to scan the entire system or individual files whenever necessary.

Computer threats: research task (Coppellotti,

Lamanuzzi,Broshka, Giulio)

Antivirus software

Most programs also protect against other types of malware and may also be bundled with firewall features.

According to the functions available, antivirus software can be classified as follows:

● stand-alone antivirus software: only removes viruses; ● malware protection antivirus software: which combines virus detection with malware and spyware protection; ● antivirus software security suite: a package of antivirus and firewall protection;