scareware

[skair-wair]
noun
  1. Computers. software that is sold as computer security or as an antivirus or other utility program but is either useless or is itself malware: I was a victim of scareware—I got a warning that my computer was about to fail, so I panicked and purchased the advertised software, which wiped my hard drive instead of fixing it!

Origin of scareware

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018