The first step in dealing with a scareware is to understand what has just happened to your computer. Victims often ignore or miss the signs of a rogue AV infection. This is especially true with scareware, which tries to fool you into believing that it is a legitimate program trying to help you with a virus infection. Thinking about scareware as a malicious program and treating it like a virus will put you on the right track, says Nicolas Brulez, a senior malware researcher at Kaspersky Lab.
Source: https://threatpost.com/step-1-understand-the-problem/91807/