恐吓软件是一种商业性质的软件。通常分为两种，一种随电子邮件上下载下来或触发的，另一种为假冒安全软件。 最有名的为Spyware，当你运行扫描动作，他会告诉你电脑上有千种甚至万种病毒在不安全防护下，须立刻付费注册并运行清理。但若你卸载后改用其他安全软件，则发现才五百左右危险性，根本没有像前者所述。

随电子邮件上下载并安装的，则有谎称自己是保密软件。输入密码可以解锁使用电脑，初期引人入目，也可防范小孩子乱玩。但随试用期时间过去，他会开始恐吓你若不付费，将会损害电脑内的信息。但专家指出只是恐吓软件，用不同手段，磁盘内仍可找出已存盘案。

Scareware is a form of malicious software that uses social engineering to cause shock, anxiety, or the pe****tion of a threat in order to manipulate users into buying unwanted software. Scareware is part of a class of malicious software that includes rogue security software, ransomware and other scam software with malicious payloads, which have limited or no benefit to users, and are pushed by unethical marketing practices. Some forms of spyware and adware also use scareware tactics.