Packers
We may use packers in the context of On-Disk Antivirus Evasion. One of the earliest ways of avoiding detection involved the use of packers. Given the high cost of disk space and slow network speeds during the early days of the internet, packers were originally designed to reduce the size of an executable.
UPX
Even though some modern malware uses a variation of this technique, the use of UPX and other popular packers alone is not sufficient to evade modern AV scanners.
The Enigma Protector
Among commercially available tools, The Enigma Protector can be used to successfully bypass antivirus products. Enigma Protector is a powerful system designed for
comprehensive protection of executable files