Scams through downloads

In brief

The Web is a source of all kinds of inexhaustible treasures, for browsing or download.

Increased bit rates have made downloads faster and easier. An information document or a PDF form downloaded from an official website is not normally a problem.

The problem arises when some websites offer file downloads that will result in unwanted or even harmful effects on our computer. Healthy programs downloaded a long time ago can also be problematic if they contain flaws that have not subsequently been corrected.

Overview of threats

Viruses

The virus is the oldest and most traditional form of malicious program. Viruses can hide in any type of file, document, image or video. They interfere with the operation of the computer or simply prevent it from functioning altogether. Their role is essentially destructive and they are not the best way to make money for their authors.

False viruses and fake antiviruses

False alerts exploit our fear of infection by a real virus. A malicious site may, for example, display an alert that makes us believe that our computer is infected. If we click on the alert, we will be advised to download a pretend antivirus which is actually a malicious program such as a “Trojan horse”. If this program is downloaded, it will hide on our computer and will probably have no visible effect. However, the perpetrator will be able to take control of our computer, possibly for unlawful purposes.

Secuser has compiled a list of fake viruses: Secuser

Microsoft ‘s advice for thwarting false alerts: Microsoft Blog - Real vs. Rogue Security Software – Can You Tell The Difference?

Videos and players

Players are programs that we use to play audio or video files. There are many types of player. Most of the time, they work properly. But there are 2 types of problems with them:

  1. Old players that are not updated may contain flaws that are exploited by downloaded video or audio files.
  2. Illegal download sites force their users to install a specific player or program in order to download the video file “faster”. This player normally incorporates malicious code. Also, we should be aware that files downloaded from illegal sites may themselves contain malicious code. Avoid!

Download videos faster

Plugins

Plugins are usually not dangerous in and of themselves. However, we need to be aware that they are just like any other software and may, therefore, have flaws and vulnerabilities. It is therefore important, when downloading files, to check that they are legitimate and that they work as advertised. Then they need to be updated regularly, as does the browser used to install them.

Finally, plugins that are no longer used should be removed. In short, infections can be avoided by following some hygiene rules with plugins as with any program installed on your PC.

Adware

When some downloaded programs are installed, adware may be installed with them, causing pernicious advertising to be displayed on the computer, either on browser bars, in pop-up windows or system messages. Even if these programs are not really malicious, they slow down your PC and can make it vulnerable.

Zombies

Some types of downloaded malware can turn your PC into a “zombie” that can be used by hackers to perpetrate attacks without being detected.

Ransomware

Other malicious files have the effect of encrypting the data stored on your hard drive. You then no longer have access to it and have to pay a substantial sum to decrypt your own data to regain access to it. This is the supreme scam!

How can we protect ourselves

The slogan “Clever Klicken” is more relevant than ever for addressing the download risks. The following responses and measures should be adopted.

Behavioural measures
  • Beware of unsolicited emails and attractive offers on the Web or any unsolicited file sent by email or on social networks. Learn to resist social engineering in general.
  • If in doubt, ask for confirmation before opening a file.
  • Find out how to recognise messages from your own antivirus software. Many malicious sites trick internet users into downloading fake antivirus software by claiming that the user’s machine is infected.
  • Pay attention to alerts issued by search engines or browsers when they warn you against navigating on a certain page.
Technical measures
  • Use a navigation filter such as WOT or enable your browser filters:
    • Microsoft Smart Screen
    • Mozilla Firefox phishing filter
    • Google Chrome and browser safety
  • Install a web filtering solution for your company, thereby instantly blocking a lot of malicious websites.
  • Use virtualisation or a similar solution to contain potential threats (for example, see Sandboxie)

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