Methods to hex edit binary files via Powershell

Question

Am trying to perform binary hex edit from the command line using only powershell. Have had partial success performing a hex replace with this snip. Problem springs up when

Answer 1

You already have a byte array, so you could simply modify the bytes at any given offset.

$bytes  = [System.IO.File]::ReadAllBytes("C:\OldFile.exe")
$offset = 23

$bytes[$offset]   = 0xFF
$bytes[$offset+1] = 0xFF
$bytes[$offset+2] = 0xFF

[System.IO.File]::WriteAllBytes("C:\NewFile.exe", $bytes)