Antivirus products and End Point services today generally speaking comes with two ways of detecting malware: signature-based Heuristics and signature-free software. However, even with the combined strength of signature-checking and heuristics, they have a hard time detecting one-type of malware, the type that does not use a file stored on the storage device for it to operate. Fileless malware is a type of malicious software that uses legitimate programs to infect a computer. Organizations need to adopt an approach to cybersecurity that combines user behavior, processes, and technology.”]
Source: https://hackercombat.com/fileless-malware-the-archilles-hill-of-traditional-antivirus-software/