binary opeations:
    $a -band $b and
    $a -bnot $b not
    $a -bor $b or
    $a -bxor $b xor
    $a -shr $b right shift
    $a -shl $b left shift

xor on a byte array:
    for($i=0;$i -lt $bytes.count;$i++){$bytes[$i]=$bytes[$i] -bxor 0x6A}

convert string to byte array:
    $bytes=[System.Text.Encoding]::UTF8.GetBytes($secret)
convert byte array to string:
    $string=[System.Text.Encoding]::UTF8.GetString($bytes)

a xor b can be reversed by the same exact operation

$shellStr = "echo henloamf";


$sillystring='henloloamf';$sillyxorkey=0x3b;$bytes=[System.Text.Encoding]::Unicode.GetBytes($sillystring);for($i=0;$i -lt $bytes.count;$i++){$bytes[$i]=$bytes[$i] -bxor $sillyxorkey};$string=[System.Text.Encoding]::UTF8.GetString($bytes);$string

$sillyxorkey=0x3b;$bytes=[System.Text.Encoding]::Unicode.GetBytes($string);for($i=0;$i -lt $bytes.count;$i++){$bytes[$i]=$bytes[$i] -bxor $sillyxorkey};$string2=[System.Text.Encoding]::UTF8.GetString($bytes);$string2

[char]0x0048 manually encoded unicode

$encoding = [System.Text.Encoding]::UTF8
$input = 'input string thingy'
$output = $encoding.GetBytes($input)

$bytes = [System.Text.Encoding]::UTF8.GetBytes($input)
$string = [System.Text.Encoding]::UTF8.GetString($bytes)


# encode to bytes
$in = "input string thingy";
$bytes = [System.Text.Encoding]::UTF8.GetBytes($in);

# decode from bytes
$str = [System.Text.Encoding]::UTF8.GetString($bytes);
$str;

# encode to bytes and xor
$key = 0xA3;
$str = "echo hemanloanf";
$bytes = [System.Text.Encoding]::UTF8.GetBytes($str);
$bytes;
for($i = 0; $i -lt $bytes.length; $i++) {
    $bytes[$i]=$bytes[$i] -bxor $key;
}
$bytes;

# decode back to string
for($i = 0; $i -lt $bytes.length; $i++) {
    $bytes[$i]=$bytes[$i] -bxor $key;
}

$str = [System.Text.Encoding]::UTF8.GetString($bytes);
$str

# xor obsfuscation and exe oneliner
# encode
$key = 0xA3;
$str = "echo hemanloanf";
$bytes = [System.Text.Encoding]::UTF8.GetBytes($str);
for($i = 0; $i -lt $bytes.length; $i++) { $bytes[$i]=$bytes[$i] -bxor $key; }

# xor encode oneliner
$key=0xA3;$str="echo hanloand";$bytes=[System.Text.Encoding]::UTF8.GetBytes($str);for($i=0;$i -lt $bytes.length;$i++){$bytes[$i]=$bytes[$i] -bxor $key;};
# $bytes

# decode and execute oneliner
$key=0xA3;for($i=0;$i -lt $bytes.length;$i++){$bytes[$i]=$bytes[$i] -bxor $key};$str=[System.Text.Encoding]::UTF8.GetString($bytes);
# $str