APTs are arguably the most dangerous security concern for business organizations today, given their targeted nature. An APT attack is typically launched by a professional organization based in a different country than the victim organization. The question isn’t whether you’ve been compromised by an APT, but whether you have noticed it. Identify the most relevant weaknesses, fix them, then change the passwords, best defense, says IT expert John Defterios. The company’s systems were completely compromised, so new laptops and wireless routers were purchased.”]
Source: https://www.csoonline.com/article/2134404/6-lessons-learned-about-the-scariest-security-threats.html