Software that attempts to cause damage on a computer. This can include the interception of communications, the theft or destruction of data or the manipulation of an e-banking transaction.
Attackers try to infect other people's computers with malware. This often happens through email attachments or by tricking people into downloading what looks like free software. Malware is often designed to download additional components, allowing attackers to further compromise the infected system. Infections can be hard to detect – signs include a noticeably slower system or increased network activity. Don't rely solely on antivirus software. If you suspect your device has been infected, have it checked by a professional.
Specific measures
Preventive measures
How the NCSC can help
Further Information
- If you suspect your device is infected with malware, have it examined by a specialist.
- The changes that malware makes to a system are often difficult to undo. In the event of an infection, therefore, the entire system should be reinstalled. Regular backups will help prevent data loss.
- After the reinstallation, change your passwords for all online access (email, social networks, etc.), as the malware may have given the attackers access to them.
- Outdated operating systems and software are prime targets for attacks. Ensure that all devices (e.g. PCs, laptops, smartphones, tablets) automatically install available security updates.
- Activate your device's built-in firewall before connecting it to the internet or any other network.
- Use up-to-date antivirus software and run regular full system scans – but keep in mind that even current antivirus tools cannot detect every threat.
- Only install the programs and apps you need and always download them from official sources.
- Be cautious of emails that ask you to take action, such as clicking a link or opening an attachment.
- Malware can also be distributed via Office documents (e.g. Word, Excel, PowerPoint). These often exploit the macro function. Never allow macros to run in documents from the internet.
- You should always enable two-factor authentication (2FA) for services that offer it. This will increase the security of your data considerably.
- Make regular backups. Backups can help you to restore your system if it becomes infected.
- If a website is spreading malware, the NCSC will contact the hosting provider to have the malicious content removed. If it is a .ch or .swiss domain, the NCSC can have the website blocked directly.
- The NCSC can place domain names and IP addresses used in connection with malware on blocklists to protect other users.
- Your report via the online form helps the NCSC identify trends. This makes it possible for the NCSC to raise public awareness in a targeted way.
Last modification 09.10.2025
