Packing an executable is similar to applying compression or encryption and can inhibit the ability of some technologies to detect the packed malware. High entropy is traditionally a tell-tale sign of the presence of a packer, but many malware analysts may have encountered low-entropy packers more than once. The authors of this research paper will be presenting their work at NDSS on February 26th, 2020. They say packers are not negligible and must not be ignored in future studies. They conducted a systematic study over a curated dataset of 50,000 malicious PE files.”]
Source: https://blog.talosintelligence.com/2020/02/new-research-paper-prevalence-and.html