Hackers are abusing Excel 4.0 macros to spread Z loader and Quakbot malware. 90% of documents with malicious Excel macros were found to be malicious. The macros are a legacy scripting language that was first launched in 1992. Hackers target Excel macros because it provides paths to access all the powerful functionalities like interaction with the operating system (OS) But, if users encounter a document that generally contains XLM macros, then it confirms that its macro will be malicious. Thats why the hackers try to convince their targets to allow macros so they can easily decrypt the content.”]
Source: https://gbhackers.com/hackers-abuse-excel-4-0-macros/