Best Free Antivirus Software (2023)

A cyberattack is any aggressive action targeting a computer information system, network, infrastructure, or personal device (carried out in order to modify, delete or steal data):

#1 Phishing

An email is sent pretending to be from a trusted sender, in order to get personal information or to motivate the target to do something specific.

You might download an attachment from the email that actually contains secret malware, and infects your computer.

What is Spear Phishing?

It’s much more targeted. Attackers research the target in detail and craft messages that seem very personal and relevant. Of the two, spear phishing is much harder to identify and shield against.

Hackers may spoof the ‘From’ part of the email so it seems to be coming from a company you have dealings with - or even clone websites. This is to trick you into entering personally identifiable information (PII) or steal login details:

• Hover - hover over any links but do not click: just hover to see the link’s URL
• No haste - take time when in your inbox, to improve your analytical reasoning
• Headers - pay attention to these: the return-path & reply-to should be the same
• Sandboxing - this lets you risk-free test an email you suspect

#2 Denial-of-Service (DoS) / Distributed Denial-of-Service (DDoS)

A DoS attack cripples a computer system’s resources so it can no longer meet service request demands.

A DDoS is larger-scale and also directly attacks system resources, spreading malware from other machines controlled by the cyber-attacker.

Botnet attacks use millions of systems infected with malicious code, all under a hacker’s administration.

These attacks do not give the attacker any access; rather, it sends the target into downtime. This may be in order to compete against a business competitor, which can also be accomplished by destroying their resources.

Some variations of DoS and DDoS are: ping of death, smurf, teardrop, PCP SYN flood, and botnet attacks.

#3 Man-in-the-Middle (MitM)

Whenever a hacker places themselves in communications between a server and a client, this is known as a MitM attack:

• Session hijacking MiTM - when the hijacker takes the client’s IP address and attaches it to their computer
• IP spoofing MitM - also involves substitution, used in order to receive/send data packets from/to the target.
• Replay MiTM attack - messages are intercepted and resent, pretending to be one of the actors in the original session.

#4 Malware Attacks

The term malware is generally known as malicious software, which is any piece of undesirable software installed into your system without your approval. Oftentimes, it hides inside trustworthy codes (such as programs) and spreads in secret:

• File infectors.
• Macro viruses.
• System/boot-record infectors.
• Stealth viruses.
• Polymorphic viruses.
• Trojans.
• Worms.
• Droppers.
• Logic bombs.
• Ransomware.
• Adware.
• Spyware.

How Do Ransomware Attacks Work?

Ransomware hijacks a person's files/computer system, blocking the user from accessing it. The information is encrypted, holding this data hostage Without a key to unlock it.

The goal is to make the victim have to pay the ransom amount in order to get the decryption key, so that the block can be released.

Many times, the victim pays the ransom yet still isn’t given the key. In order for the cyberattacker to stay anonymous, they often require ransom payment in some form of cryptocurrency such as Bitcoin, making it harder to track them down.

In 2019 alone, roughly 2,400 ransomware attacks cost the US £5.9 million (the FBI and Europol both consider ransomware to be a big digital threat, with Europol naming it the main cyber threat for 2019 - although it's been a terror for the last 30 years):

Famous Ransomware Attacks:

Ryuk (2018-2020) - “Ryuk” ransomware attackers used phishing to hold victims ransom: malicious emails with infected/criminal links and attachments. These attacks led to £44 million worth of damage globally since 2018, targeting 100+ companies (notably, EMCOR, an engineering and industrial construction organization, was affected).

SamSam (2018) - an attack mostly infected the city of Atlanta (who alone had to spend £1.5 million to recover), Colorado and San Diego. It was later used by Iranian hackers, who targeted over 200 companies in the US & Canada.

This led to £22 million in damages. Attackers asked victims to make a payment for the first decryption key, to prove that they would actually provide the other decryption codes.

WannaCry (2017) - an apt name: one of the worst ransomware attacks to ever occur. This led to £3 billion in losses and used emails, in order to scam 200,000+ companies and people, including Nissan, Renault and FedEx. With that four billion in losses, each machine needed £220 to be released.

But if you think that’s a lot, the 2016 Petya ransomware attacks have caused 10 billion dollars in financial losses since its release!

#5 Six More Common Types of Attacks

Birthday Attack

Which works against hash algorithms Useful verifying signatures, software and messages.

Cross-Site Scripting (XSS)

Which runs scripts in your browser or scriptable application.

SQL Injection Attack

Lets attackers read sensitive data from website databases, or even issue commands. Learn more about NoSql Injection attack!

Password Attack

Sniffing out user passwords via social engineering, guessing, or getting access to a passcode database.

Drive-by Attack

Spreading malware by looking for websites with poor security and embedding malicious scripts into the PHP or HTTP code at the top of the page: this either installs malware or redirects to spoof websites.

Eavesdropping Attack

Based on network traffic interception, in order to gain credit card numbers, passwords, and other pieces of confidential data transmitted over a network.