Rogue security software is an application that appears to be beneficial from a security perspective but provides little or no security, generates erroneous alerts, or attempts to lure users into participating in fraudulent transactions. Some products defined as "rogue" simply fail to provide the reliable protection that a consumer paid for. Others are far more sinister, masquerading as legitimate security software, and using deceptive tactics to con users into buying the product.

While rogue security software may appear in a variety of shapes and sizes, the majority of rogue security applications put users at increased risk in multiple ways. First, regardless of its promises, rogue security software simply does not protect against security threats. Second, rogue security software may actually install malicious code that makes users vulnerable to Internet threats. Third, the scammers who peddle the rogue security software may also use the personal information provided by the victim to commit fraud. And fourth, rogue security software weakens a user's security posture-by instructing the user to disable legitimate security software in order to register the bogus product, or by preventing the user from accessing legitimate security websites.