Adobe Acrobat XI Pro is ancient software that is no longer safe to use, even if legitimate:

Select your preferred language and choose the installation folder path (the default is typically recommended). Installation Type:

Released in late 2012, was the final version before Adobe transitioned to the "Document Cloud" (DC) subscription model. It was highly prized because it was the last version available as a perpetual license , meaning users could pay once and own it forever rather than paying a monthly fee. Key features of version 11.0.0 included:

Early implementation of "Send for Signature" workflows. Decoding the Search Term

as malicious, with a detection rate of over 50% across various antivirus engines. End of Life (EOL)