You can open or rather import Microsoft Publisher documents (.pub) files to Adobe InDesign with the help of specialized plugins from Markzware and then save them to INDD format. Not perfect, but it seems like the only direct way how to achieve pub to indd conversion.
Convert Microsoft Publisher document to Adobe InDesign document.
We have found 2 software records in our database eligible for .pub to .indd file format conversion.
Articles and other information relating to pub into indd conversion:
How to convert Adobe Indesign, QuarkXpress, or Microsoft Publisher documents between each other - Conversion of INDD, PUB and QXP fiormats with Markzware Plugins and Xtensions.
Microsoft Windows software - convert pub to indd on Windows
A plugin for Adobe InDesign that add support for Microsoft Publisher files
Convert from pub file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned pub to indd. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Apple macOS / Mac OS X software - convert pub to indd on OS X
A plugin for Adobe InDesign for Mac that add support for Microsoft Publisher files