You will need to be on the lookout for the virus, FBI Moneypak Ransomware. The virus locks your computer and prevents you from being able to use your computer. The virus makes you believe that the lock out is from the FBI or other Local Authority.
To prevent being affected by the virus, make sure your virus software definitions are up to date and that your computer updates are current. Also, be aware of web links that you open on the web, including those that are posted in social media sites. Do not open web links in emails from senders that you do not know or emails that do not have a subject line or have a blind sender.
If you have been infected, you can take your computer to a local repair depot to have them professionally remove the virus or look up how to remove the FBI Moneypak Ransomware on google, bing, yahoo, ect.