If you have a legitimate license key for Acrobat XI Pro and you need to run it on an isolated, offline virtual machine, finding the 11.0.27 official .msp file on a trusted archive (like the Internet Archive) might be acceptable. However, if this machine touches the internet, you are risking your data.
Using unpatched or EOL software makes your system vulnerable to modern malware delivered via PDF files. Adobe Help Center Purpose of the 11.0.27 Patch Adobe Acrobat XI Pro 11.0.27 Patch
: Updates for version 10.x and later are typically cumulative, meaning a single patch can update an existing installation to the latest available state without requiring multiple intermediate steps. End of Life Risks If you have a legitimate license key for