What is:Malware/fr

Qu'est-ce que Malware

Malware - est un nom commun à plusieurs types de logiciels, conçus pour accéder sans autorisation à des appareils informatiques (ordinateurs, smartphones, etc.) ou à des réseaux et/ou nuire intentionnellement aux utilisateurs de ces appareils. Ainsi, un logiciel est défini comme un logiciel malveillant, selon le but de son utilisation, plutôt que selon la méthodologie ou la technologie particulière sur laquelle ce logiciel est basé.

Finalités d'utilisation

Les premiers programmes malveillants ont été créés à titre expérimental ou pour le plaisir. Aujourd'hui, les logiciels malveillants sont le plus souvent utilisés pour voler des informations - financières, personnelles ou professionnelles. Les logiciels malveillants peuvent être utilisés à la fois pour des attaques contre des organisations (pénétration dans un réseau local) et même sur un pays, ainsi que pour voler des informations particulières sur un individu (vol de données bancaires, accès à divers services, etc.).

La plupart des virus et vers existants sont conçus pour prendre le contrôle de l'appareil attaqué (ordinateur, smartphone, etc.). Après cela, l'appareil surveillé peut être utilisé pour envoyer du spam, stocker des informations illégales (par exemple de la pornographie enfantine) ou pour effectuer des attaques d'autres types.

Classification des logiciels malveillants

Certains produits malveillants peuvent appartenir à plusieurs types à la fois; ces programmes ont souvent des traits de chevaux de Troie et de vers, et parfois aussi des virus. En règle générale, un programme malveillant est remis à l'utilisateur final sous la forme d'un cheval de Troie, mais après son lancement, il se corrige sur l'appareil de l'utilisateur et infecte les fichiers exécutables d'autres programmes, c'est-à-dire qu'il agit comme un virus; il peut également attaquer d'autres appareils sur le réseau, c'est-à-dire agir comme un ver.

Viruses

A computer virus is a program hidden in other software, usually useful or harmless. Viruses are able to create copies of themselves and insert them into executable files of other programs. A virus usually performs some malicious action - for example, data theft or destruction.

Worms

A computer (network) worm is software that copies itself to other computers through a computer network in order to distribute itself. Usually, gaps in operating systems or network settings are used for this.

Spyware

Spyware is software whose purpose is to steal private information from a computer system for a third party. Spyware collects the information and sends it to an attacker.

Trojan horses

A Trojan horse (or simply 'a Trojan') is a malicious program that disguises itself as a regular useful program or an app to convince the victim to install it. A Trojan horse usually carries a hidden destructive function activated when the Trojan-laden application starts. The term is derived from an ancient Greek story about a Trojan horse used to covertly invade the city of Troy. Unlike computer viruses and worms, Trojan horses usually do not try to embed themselves in other files or otherwise spread themselves.

Logic bombs

A logical bomb is a malicious program that uses a trigger for activating malicious code. A logic bomb does not work until this trigger event occurs. Once launched, a logic bomb injects malicious code that harms the computer. Cybersecurity experts recently discovered logic bombs that attack and destroy equipment components on workstations or servers, including cooling fans, hard drives, and power supplies. The logic bomb overloads these devices until they overheat or fail.

Ransomware

A screen blocker is a pseudo-police program that locks the screen on the device and informs the user that he or she is ostensibly accused of collecting illegal content, trying to scare the victim and make him or her pay the "fine".

Rootkits

A rootkit is a malicious program that hides its presence with the help of a low-level modification of the infected system. Rootkits can prevent the appearance of their executable process in the list of system processes or block reading of their files.

Backdoors

A backdoor is a malicious program that provides access to the infected device by means of bypassing normal authentication procedures, usually through a network connection. After a system (computer or subnet) is hacked, a backdoor can be installed to provide access to the hacked system in the future, invisibly to its user.

Adware

Adware is a type of malware that redirects your browser to an advertising web page without your consent. Often these pages try to download other malware. As cyber security experts say, adware is often found in so-called free programs, such as games or browser extensions.

Cryptojacking

Cryptojacking is malware that uses power of your device (e.g. computer) to mine cryptocurrencies without your knowledge. Such mining software may run in the background on your operating system or even like JavaScript in a browser window.

Malvertising (Malicious Advertising)

Malicious advertising is using legitimate advertisements or ad networks to deliver malware. For example, a cybercriminal may pay for placing an advertisement on some website. When a user clicks on this ad, the code in the ad either redirects the user to a malicious website or installs malware on the victim's computer. In some cases, malware embedded in such ads can run automatically without any user’s action - this method is called "boot from disk".

Methods of Infection

Security Gaps in Software

Malicious software may use security flaws (vulnerabilities) in the operating system, individual applications, or application extensions (plug-ins). A common method of infection is to exploit the buffer overflow vulnerability.

Overly privileged users and overly privileged code

In computer systems, different users and programs have different privileges as to how they can influence the system. In poorly designed systems, users and programs can be given too high privileges without explicit need for it, and malicious software can take advantage of this.

Insecure system settings or user errors

Insecure settings include, for example, ability to autoload from removable media (USB, CD, DVD, etc.). User errors are actions of the device user, which lead to infection. Most often, these actions include launching programs of dubious or obviously dangerous origin (cracks and keygens for paid software, opening email attachments, etc.) without checking them first.