Viral videos can lead to computer repair needs primarily by tricking users into downloading malicious software, such as viruses or adware, often disguised as necessary plugins to view the content. A common scam involves enticing social media users with sensational videos, like the 'Girl Killed by Husband' video reported by Bitdefender, which then prompts them to install a fake plugin that is actually a virus. This infection can cause pop-ups, access non-personally identifiable information, and open the door to more severe malware, ultimately requiring professional computer repair services to clean and secure the machine. Users are advised to avoid clicking on unknown video links or downloading unverified plugins to protect their systems.