"Automated dynamic unpackers run the executable and allow the unpacking stub to unpack the original executable code. Once the original executable is unpacked, the program is written to disk, and the unpacker reconstructs the original import table."

What is the point of UPX?

UPX works by compressing the sections stored within the Section Table of the PE file. A strong indicator of UPX being used is the renaming of the header names (UPX0/UPX1). The main purpose of UPX is to reduce file size, this helps mask the malware as a . jpg or to spread through emails.

What is an unpacker?

Filters. One who, or that which, unpacks. noun. (computing) A software program that decompresses code or data.