Malicious software (English: malware) is any program code or file created to damage a system, disrupt its operation, gain access or unlawfully collect data. In the context of websites, this is especially relevant because an infected website may not only stop working, but also pose a risk to visitors, staff and the institution’s reputation. In the European public sector — on municipality, school, museum, library and other organisation websites — such incidents can have wider consequences, because public information is often published, electronic services are provided or personal data is processed.
How does malicious software appear on a website?
Malicious software is not always visible straight away. Sometimes a website appears to work normally, but unauthorised actions are taking place in the background: spam is being sent, hidden links are being inserted, login details are being collected or visitors are being redirected to other websites. That is why it is important not only to react to obvious disruptions, but also to check the website regularly.
- Backdoor (slaptoji prieiga)
This is malicious code that allows an attacker to return to the system even after passwords have been changed or part of the infected files has been removed. Such access is often hidden among normal website files, so without a thorough check it can be difficult to detect.
- Defacement (turinio pakeitimas)
In this case the visible website content is changed — the home page, news or other sections. For public-sector organisations this is especially sensitive, because even a short-term content change can mislead residents and reduce trust in the institution.
- SEO spam (hidden links)
Links or pages are inserted into the infected website for promoting other projects in search engines. They are often invisible to the ordinary visitor, but they damage the website’s reputation and can lead to poorer search visibility.
- Redirects (peradresavimai)
Visitors are automatically redirected to other pages, which may be linked to fraud, advertising or malicious content. Such redirects are especially dangerous because they affect not only the institution itself, but also its website users.
How are websites infected?
Websites are most often infected through vulnerable plugins, out-of-date content management systems, weak administrator passwords or a server environment that has been configured insecurely. WordPress websites are a frequent target not because the system itself is insecure, but because it is widely used and often maintained unevenly. If an organisation does not update plugins, themes or the system itself for a long time, the risk increases significantly.
In the public sector, additional risk is created by multiple suppliers or staff members having access to the same website. If there is no clear responsibility structure, two-factor authentication or access control, malicious code can be installed unnoticed. That is why not only technical solutions matter, but also clear internal processes.
Why does this matter for the public sector?
Websites of municipalities, schools, libraries or museums are often the main source of information for residents. If such a website becomes infected, service delivery may be disrupted, misleading information may be published or the institution’s image may be damaged. In addition, if personal data is processed on the website — for example, in registration forms, newsletter subscriptions or contact enquiries — the incident may also have GDPR compliance consequences.
In such cases, it is important to assess whether the confidentiality, integrity or availability of data has been compromised. If there is a suspicion of a personal data breach, the organisation must act according to established procedures: record the incident, assess the impact and, where necessary, inform the responsible persons and supervisory authorities.
How to detect malicious software?
To detect malicious software, security scanners are often used, for example Wordfence, server log analysis, file change monitoring and manual code review. Automated tools alone are not always enough, because some threats are designed to hide from standard checks. That is why it is useful to carry out a security audit periodically, especially if the website is important for the provision of public services.
Signs that a website may be infected can vary: unexpected redirects, unusually slow performance, search engine warnings, unexplained file changes or administrator accounts that nobody created. The earlier the problem is identified, the smaller the damage to the organisation and its visitors.
Prevention and good practice
The most effective protection against malicious software is consistent prevention. This means regular updates of the system, plugins and themes, strong passwords, two-factor authentication, backups and limited user permissions. For public-sector organisations, it is also important to have a clear division of responsibilities: who maintains the website, who approves changes and who responds to incidents.
Equally important are accessibility and reliability. If, after a security incident, the website becomes unavailable or some functions stop working, this directly affects residents’ ability to access information and use services. Security should therefore not be treated as a separate technical topic — it is one of the essential parts of a high-quality, legally compliant and reliable public-sector website.