PUP.Optional.Firser.A is a threat detected by MalwareBytes Anti-Malware. The PUP.Optional.Firser.A threat is classified as PUP a Potentially Unwanted Program by MalwareBytes Anti-Malware because it inflicts and acts as a malicious threat into your computer system. PUP.Optional.Firser.A is not a virus but it does act like one. PUP.Optional.Firser.A is adware which is bundled using custom installers and dropped on your computer during the installation process. Most users have no idea how this PUP.Optional.Firser.A threat is installed on there computer and what it is, until MalwareBytes Anti-Malware detects it as a malicious threat or virus. Follow our instruction to remove this PUP.Optional.Firser.A threat from your computer.