RESEARCH BY PHILIP TSUKERMAN
Excel 4.0 macros (XLM), the older, awkward sibling of VBA, have been the focus of a couple of interesting offensive techniques. Since Stan Hegt and Pieter Ceelen of Outflank first played with the feature, and we have abused it for a funny little lateral movement technique and they have evolved to do some impressive work weaponizing it as a shellcode runner.
Article Link: https://www.cybereason.com/blog/excel4.0-macros-now-with-twice-the-bits