Types of malware and what they do in the most common scams

03/02/2022

Malware, which includes what are commonly known as viruses, is computer code that infects and disrupts devices, disables systems and steals information. In this, the latest post in the series “Protect yourself against scams”, we get a little technical and explain the main types of malware with a few examples.

• A virus uses malicious code in an attempt to disrupt the normal functioning of a system. Its main characteristic is that it must be introduced by a user.
• Worms are characterised by their ability to replicate themselves, spreading from one computer to another without any human intervention. They tend to cause network problems.
• Trojans are similar to viruses and pass themselves off as legitimate software, but they also include a feature that enables remote control or the installation of “back doors” to gain access to devices.
• Ransomware blocks system access, encrypting the user’s information and demanding a ransom payment before decrypting it. It is usually targeted at businesses.
• Botnets are networks of infected computers that can carry out attacks such as password theft, mass spamming or Distributed Denial-of-Service (DDoS) attacks, among others. Some botnets run cypto mining software, slowing down your device and using up resources.
• Spyware gathers information on a user’s browser history, passwords and other personal and banking details. Examples include keyloggers, which log every keystroke you make, before sending the sequence to a cybercriminal.
• Adware causes your browser to display pop-ups, which contain unwanted advertising or change your default search engine.

There are plenty of other types of malware, which, generally speaking, may share one or more characteristics or may be impossible to classify.

Unfortunately, the banking world has not escaped unscathed. Examples include Trojans that install a fake security module. It usually gets onto a device when a user runs or installs untrustworthy files or applications. The Trojan detects when a client accesses their online banking and launches a pop-up indicating that a security module bearing the bank’s logo and the name of legitimate software is being installed, before asking for credentials (passwords or OTPs) in order to make payments.

Make sure you keep an eye out for the security warnings published both on the Oficina de Seguridad del Internauta (OSI) websiteAbre en ventana nueva and by your own bank in order to keep up to date with these types of scams.