The software may open a "backdoor," allowing an attacker to control your computer remotely or use it as part of a botnet. How to Protect Your System

Unofficial versions of existing software, such as the open-source Flamingo IM project, which have been altered by a third party. The Risks of "Hack" Executables

Use reputable scanners like Malwarebytes to check for "Generic.Malware" or "Suspicious" signatures.