While searching for new scenarios to deliver their malwares[1][2], attackers launched a campaign to deliver malicious code embedded in Microsoft Publisher[3] (.pub) files. The tool Publisher is less known than Word or Excel. This desktop publishing tool was released in 1991 (version 1.0) but it is still alive and included in the newest Office suite. It is not surprising that it support also macros.
https://isc.sans.edu/forums/diary/Malware+Delivered+via+pub+Files/21443/
Credits: SANS ISC InfoSec Forums