A complex attack, referred to as an advanced persistent threat or targeted attack, is a series of covert and continuous computer intrusion processes usually carried out by a highly advanced and well-organised hacking group with adequate resources (both financial and technical) to undertake such activities.

A type of malware that intrusively displays advertisements unwanted by the user (in the form of pop-ups or a system window that can’t be closed). The term also refers to a type of software licence, distributed free of charge, whose authors are paid for including advertisements commissioned by sponsors in the program.

Hacking a mobile device by using Bluetooth technology. It occurs in three forms – bluejacking, bluesnarfing, and bluebugging.

It occurs following the pairing of the hacker's device with that of their victim (via Bluetooth). The attacker then instals a backdoor code or malware to bypass the authentication process (usually by exploiting vulnerabilities in the mobile device's outdated operating system) and gains full access to the laptop or phone. This allows reading messages, making calls, or even redirecting calls to other devices belonging to the cybercriminal.

Sending unwanted messages via Bluetooth.

Gaining access to text messages, calendar, contact book, etc. by exploiting flaws in the attacked device's software, or by gaining the ability to establish an authorised connection with it via Bluetooth (usually by gaining physical access to the device or the victim's unwitting consent), or obtaining data via a "back door" created by deliberately setting up the victim's device to connect to the cybercriminal's device.

A type of malware that, when triggered, injects its own malicious code into other files or programs to spread through the infected host. This occurs when applications infected in this way are run, with the malicious code running first, replicating further and causing other damage, such as corrupting system files, deleting data, or attempting to take control of the device.

Attacks that exploit weaknesses in cryptographic algorithms. The attack vectors can be very different here, depending on the circumstances of the hacker's actions. They may concern, for example, errors in algorithm implementation (e.g. SSL library used by a given website), use of outdated cryptographic protocol (e.g. SSL 2.0/3.0), or an encryption key of insufficient length (fewer than 2,048 bits).

A dictionary attack aims at cracking passwords by using software that has a built-in dictionary allowing attempts to gain access using its collection of words.

An “enhanced” (because carried out from multiple sources simultaneously) variant of a DoS attack aimed at disrupting or paralysing the network, thus preventing access to services or resources located on the server hosting them or providing necessary data.

The examination and online dissemination of private or identifiable information, particularly that making it possible to identify individuals or organisations.

An e-mail bomb is an attack that involves sending a very large number of e-mails to a given address to overflow the mailbox, overload the server on which it is hosted, or distract its owner from other activities carried out in the event of a larger-scale attack.

A program or device (e.g. physically connected between the USB plug of a keyboard and a USB port on a computer) that allows the capture of data entered using the device.

A generic term for any type of application or script designed to cause damage to a computer, server, or computer network.

An attack that modifies the cache of DNS records on a user's computer or "poisons" the DNS server to redirect the victims to a fake website.

The act of sending fraudulent e-mails with the aim of influencing the recipient’s actions to make them perform a specific action or to disclose confidential information.

Unwanted software most often installed when using download assistants included in many online software repositories or as part of the installation process of free software. It can vary in nature, being more akin to adware (aggressive advertising on the user's computer) or spyware (spying on their activity, collecting data on the use of a particular device without consent).

Malware that encrypts data on a victim's hard drive or other storage medium and extorts them to pay a ransom to unlock it.

Software designed to hide malicious files or processes that are components of other malware, thus providing a highly effective means of masking an attack or any other unauthorised activity on the computer system under attack.

A form of malware that uses social engineering to cause shock, distress, or a sense of threat to manipulate the user into performing a specific action, e.g. with a message informing them that their computer is infected to induce them to install malicious "antivirus" software.

Sending a very large number of unsolicited messages to multiple recipients for a specific purpose, such as marketing, or simply sending a particular message over and over again to the same recipient. The medium with which it’s usually associated is e-mail, but the term is also applied to messages of this nature on social networks, instant messaging platforms, online forums or via SMS messages.

Interception of an authorised user's session, i.e. the interruption of an authorised connection between two computers and subsequent replacement of the trusted host or server site by the attacker.

Phishing or accessing and controlling the victim's mobile device through the use of malicious SMS messages.

The use of computer software or hardware (sniffer) that can intercept and record traffic passing through a digital network or part of a network – eavesdropping on network traffic.

Impersonation – several hacking techniques involving the impersonation of another element of an IT system. A distinction is made between IP spoofing, ARP spoofing/poisoning, DNS spoofing/poisoning, and email spoofing.

Spyware means software designed to collect information about a person or organisation without their knowledge; it may then transmit such data to another entity without the user's consent, or provide control over the victim's device without their knowledge.

A malicious program that impersonates useful or interesting applications but performs unwanted actions without the user's knowledge. Most commonly, it acts as backdoor code, meaning that it opens a "back door" to other malware, downloading more malicious code and attempting to allow the attacker to take control of the infected machine. This can lead to confidential information being stolen (banking trojans come to mind in this context) or data being deleted or encrypted by ransomware.

Scanning a specific area for unsecured wireless networks.