Windows-Rechner in Gefahr: Nach Berliner Cyberangriff: Seien Sie bei Captchas wachsam

After clicking on "Confirm you are human" Captchas on web pages, users should be extra cautious. If no further action is required after setting the checkbox, the site is legitimate. However, if Captchas trigger keyboard shortcuts in Windows Terminal or PowerShell windows instead, the user has likely landed on a dangerous, manipulated website aiming to install malware. The Federal Office for Information Security in Germany (BSI) warns of such brand-threatening attacks.

According to the BSI, these attacks, known as Terminalfix or Clickfix, often start with a fake Captcha. Once the user confirms they are human, malicious commands are copied into the system's memory. The user is then prompted to open a Windows input field with a keyboard shortcut. They are further instructed to unknowingly copy a dangerous command from the clipboard into this field and execute it. After this, the attackers gain unrestricted access to the computer, potentially installing malware or stealing data.

In such cases, users should immediately close the browser and restart the computer to prevent the malware from deeply altering the system. This involves reinstalling the operating system and restoring personal data from backups. If no recent backups are available, the user must backup their data before a fresh start. Additionally, all online account passwords should be changed immediately, starting with email accounts, to prevent further unauthorized access.