Online security: What threatens you and how to defend yourself?

Just as we should follow certain principles of safe behaviour when we are out and about, we should be just as careful in cyberspace. Most of us certainly know that we should not open suspicious emails from senders we do not know, or download suspicious software. These are certainly good principles, but unfortunately they are not enough for one hundred per cent security. What more can you do for your online security?

What threatens you

For now, let us set aside cybergrooming and the phenomenon of online predators, which we covered in one of our previous articles. The most common risks people face online include phishing, malware (including cryptomining tools), hoaxes and spam. The exposure of your passwords and their subsequent misuse is also a considerable risk. What do these terms mean? Phishing is the term for an activity in which attackers lure sensitive data from users, related to their payment cards. Phishing can be carried out using, among other things, fake websites that pose as your internet banking. Malware is the term for harmful software – it may be viruses, trojan horses, extortion ransomware (software that can encrypt parts of your disk and demand a ransom, usually in cryptocurrency) or adware (advertising spam). 

Learn how to defend yourself

You will find plenty of articles on cyber security on the internet. Educating yourself in this area by reading various articles is certainly worthwhile, but there are also more consistent and systematic ways to acquire the right knowledge and principles of behaviour on the internet. Other forms of education in this area include various online courses, though unfortunately these are not very well known. One of these courses is run by the National Cyber and Information Security Agency (NÚKIB) itself. The course is called Dávej kyber (roughly “Be cyber-aware”), and you can sign up for it via this link. The course is completely free and suitable for all users, and you can also download it from the NÚKIB website in PDF format. If you are more interested in children's internet safety, you can let them take the course Buď safe online. 

Specific forms of threats on the internet

As we mentioned in the introductory paragraph, on the internet you are by no means threatened only by viruses, spam or phishing. Both households and businesses, offices and various institutions are at risk in this respect. As soon as your computer connects to the internet, it automatically begins to be at risk. Your computer may be targeted by attackers not only to infect it with malware – attackers may also misuse it as a means of further spreading malware, or use its computing power to mine cryptocurrencies or to communicate with other attackers. Detecting such activity is not so difficult. At first glance you may not notice anything suspicious, but you may find unusual traffic on your connection. Unusual load often occurs at the same time every day. Your home internet may suddenly slow down dramatically, and your computer and the loading of apps or web pages may also be unusually slow. Threats are not limited to households in this respect – there is a known case of a hospital, where an out-of-date version of database software had been installed on a server unrelated to patient care. The mere fact that this software was out of date was enough to give an attacker access to the system through a “hole”, and the attacker then began mining cryptocurrencies on a very powerful server. The mining was only discovered when another attacker exploited the same error to place ransomware on the server, which then tried to attack other computers connected to the network. IT experts managed to notice this activity and took the server out of operation. A deep analysis then confirmed that cryptocurrency mining had indeed taken place. Fortunately, protecting a home network is much simpler, and your internet service provider can help you with it too. Timely, regular and thorough updating of the operating system and other software and firmware is key. Updates often contain so-called security patches, which fix any errors found in previous versions of the software. Never switch off your firewall, and safe handling of emails and web links should go without saying. Taking care of the security of your computer and home network does not have to be expensive at all. If you own a computer running Microsoft Windows, the Windows Defender platform will provide sufficient protection in this respect, and it is definitely a better choice than a free antimalware or third-party antivirus. If you notice unusual load on your home network and your home internet does not reach the speed you have paid for, do not hesitate to contact your provider. Operators can use artificial intelligence (AI) to recognise possible misuse of network traffic for cryptocurrency mining, malicious communication or the spread of malware, and to resolve the problem promptly and effectively.