ZIP und Windows Defender

[Kas Ob.]

And yes one more thing about this ADS

You can hide files, yes multiple files in one file, like you can have one txt file with 2 byte in length but it have attached streams to it, where each stream is a file, and will not be visible unless you know what are you looking for, the file property will show the txt file size as 2 bytes, but size on disk a combination of its size and all its streams, so there will be huge difference not just page/cluster alignment.

you can also run an executable (EXE) directly from a stream !

These streams are reserved and Windows will copy them and move them as long the file is local, backup and restore also will reserve them, they will be lost in many cases with network or RDP.. 3rd party packers most likely will not reserve them, unless it is an archiving software like Acronis...