PUP.Optional.MailRU is a virus detected by Microsoft Windows and several other Antivirus and Anti-Malware software vendors. The PUP.Optional.MailRU heuristic detection is classified as a virus, PUP a Potentially Unwanted Program because it inflicts and acts as a malicious threat into your Windows XP, Windows Vista, Windows 7, Windows 8 or Windows 10 computer system.
PUP.Optional.MailRU modifies system files, add’s new folders, creates Windows tasks and displays advertisements on your computer and Internet Browser.
PUP.Optional.MailRU 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.MailRU threat is installed on their computer until their Antivirus or Anti-Malware software detects it as a malicious dangerous threat or virus.