PUP.Optional.Ask is Malwarebytes’ detection name for the Ask toolbar.
The Ask toolbar came with an assortment of different adware, generally installed by default. Aside from adware, Ask is known for switching your default search provider to Ask.com, and will spawn pop-up messages to prevent you from reverting the changes.
PUP.Optional.Ask was a browser extension that is frequently (and unintentionally) installed during installation of partner software. The original toolbar was most commonly bundled with Oracle’s Java installations. APN toolbars are usually installed by the users themselves, although sometimes initiated by exaggerated promises of functionality, often claiming to be helpful with your hobbies and interests. There were a plethora of toolbars and Ask.com start pages on offer for those interested, but for a price.
PUP.Optional.Ask is no longer found in the wild under that name.
Malwarebytes can detect and remove PUP.Optional.Ask without further user interaction.