How to prevent unauthorised access to your computer

Unauthorised access to a computer is essentially no different from a common burglary and is treated the same way legally. Therefore, digital security is just as important, if not more important, than traditional security measures in a company. How can data security be ensured? What methods are available? And how can unauthorised access to a computer ultimately be prevented? We invite you to explore this topic together with Anexet analysts.

What negative consequences can arise from neglecting Information Security?

First and foremost, for your own digital security, you need to clearly understand that data today is a commodity, and there will always be a queue of people wanting to get their hands on it. Malware suppliers, competitors, buyers of information for targeted attacks – they all need at least Personal Data about you and your employees. At the same time, there are significant risks associated with leaks of business-critical information (customer and supplier data, technological secrets and know-how, financial and accounting reports, etc.), which can negatively impact your business and its development.

Let's consider an example: a couple of years ago, global commerce was on the verge of collapse — an unknown computer virus paralysed the entire financial and logistical infrastructure of the planet in a matter of hours. IT giants compared the NotPetya attack to a nuclear bombing of all the capitals of global trade at once. The trigger was unauthorised access to the network of a tiny Ukrainian company called M.E.Doc, after which the NotPetya computer virus spread around the world. So, a small, little-known business became the source of a global information disaster?

As we can see, it makes no difference whether your company is a legendary enterprise with tens of thousands of employees or a small but proud office — all can become targets of attack and suffer significant damage.

Reasons for unauthorised access

A large-scale cyberattack can happen at any time, and a source could be any computer, including yours. Therefore, we suggest starting by reviewing the basic rules – the first line of defence for Information Security.

Install all security patches

According to Nomusica statistics for January 2025, more than 65% of Windows 10 users remain without security updates, exposing them to threats after the end of official support, while each scheduled update strengthens the security and protection of your confidential data. Notifications usually appear during work, so users often ignore them, thereby increasing the risk of infection and device hijacking. In addition, a computer connected to the Internet is inherently vulnerable, and no antivirus software today can guarantee 100% protection. Hackers will always find a loophole. However, timely system updates will help reduce the risk of hacking. We recommend enabling automatic updates from Microsoft. 

Control file sharing on your network

This is critically important if you use the Internet on the local network where file sharing is open to an unlimited number of people. When you connect to a LAN, you are essentially leaving the door to your home wide open, telling the whole neighbourhood about it, and going away on holiday for a few weeks. To protect your data, you should not agree to connect your personal computer to the local network, but if you need to connect, only share files and folders with users and systems you know.

Keep your firewall turned on

A firewall acts as a protective wall between you and the internet. Its main responsibility is to monitor and carefully analyse all data exchanged between your computer and the server. If a threat is detected, the "defender" will notify you. 

Use email more carefully

Read all your emails carefully and pay attention to senders. Most PC users tend to neglect email security despite being fully aware of the vulnerability of such products. In general, it is not worth opening emails received from unknown sources. Especially downloading attached files and clicking on links. 

Double-check the security of your router

Check Point experts have discovered more than 12 million routers (including top-of-the-line models) that can be hacked due to vulnerability in a mechanism for obtaining automatic settings. By implementing CWMP, an attacker can replace DNS addresses in device settings with servers controlled by the hacker. These servers filter web requests and redirect them to fake banking services (Visa, MasterCard). Since most people rarely check their router settings (or don't do it at all), the problem remains unnoticed for a long time. Usually, they find out about it when money has already been stolen from their accounts and checking their computer has yielded no results. We recommend checking your router settings more often and immediately registering alternative DNS server addresses.

Don't neglect backup copying

The main thing you should avoid is viewing important data from an infected computer. This can also give attackers direct access to your valuable and confidential information. It is recommended that you regularly back up and store duplicates of all your files in the cloud. You can be sure of the reliability of the cloud – if necessary, it can save your PC. Incidentally, a backup of the individual server of the Danish logistics company Maersk, found in time, helped defeat the NotPetya virus.

Use strong passwords

To prevent unauthorised access to confidential information, it is important to use a separate password for each of your accounts. This is especially important if you access the internet via a shared network.

Do not ignore measures to restrict physical access to PCs.

You can use more than just software solutions. The good old method of restricting physical access to a computer can also be effective. Electronic locks will act as the first physical barrier for a potential fraudster.

Virtual private networks to the rescue

One effective method of protection is the use of virtual private networks (VPNs). Let's take a closer look.

This is a method of maintaining the integrity and confidentiality of data transmission over the Internet. The main component is a VPN agent in the form of a software or a software-hardware complex that is installed on a computer and masks the user's true IP address and encrypts the transmitted data.

Essentially, a VPN replaces your address with its own, even if it is thousands of kilometres away from a sender, and also protects information "in transit" with encryption.

Use two-factor authentication

Two-factor authentication (2FA) is an additional level of data access protection that verifies the authenticity of connection and confirms the personal access level. How does two-factor authentication protect a PC from unauthorised access? The solution is quite simple, yet elegant: even if a fraudster obtains a login password, they will need the second password, which changes constantly and is only issued to an identified, recognised person at the moment of connection.

There are various combinations of two-factor authentication (2FA):

• a combination of a password and SMS or push notifications (similar to connecting/making payments in a banking app);

• a combination of a password and access certificate;

• a password, PIN code plus biometric data (fingerprint, facial biometrics, retina scan) and other.

There are a number of ready-made solutions for implementing 2FA. These include Google Authenticator, Microsoft Authenticator, WinAuth, Twilio Authy, and others.

Conclusion

Unauthorised access to a computer is an unpleasant and undesirable situation. However, we can provide means of protecting information on PCs, even using popular but effective tools. Even steps we have described above will significantly dampen the enthusiasm of fraudsters and keep your data safe.