Security News > 2020 > June > Researchers Dive Into Evolution of Malicious Excel 4.0 Macros
For more than five months, Lastline security researchers have tracked the evolution of malicious Excel 4.0 macros, observing the fast pace at which malware authors change them to stay ahead of security tools.
A central part of many organizations' productivity tools, Excel opens the door for phishing attacks where victims are tricked into enabling macros in malicious documents, which can results in the attackers gaining a foothold on the network, in preparation for additional activities.
"These macros are very straightforward and easy to create, thus easy to modify to bypass signature-based detection. Security vendors are having difficulty detecting this threat, likely due to not having solutions in place to properly assess and parse the format and structure of how these macros are stored in Excel documents," Lastline notes.
The researchers also point out that Excel 4.0 macros provide malware authors with "Near endless" possibilities, especially since they are quickly evolving, while security companies struggle to keep pace with them.
"Excel 4.0 macros continue to prove their value to attackers, providing a reliable method to get their code to run on a target. In many environments, Excel worksheets with macros are used too heavily for legitimate business purposes to disable or blacklist, thus analysts and security vendors will have to get used to consistently updating tooling and signatures as attacks continue to evolve," Lastline concludes.