PHPF*ck

funny.php

/* system(id) */
<?=$Φ=([].Φ)[![]+![]+![]]?><?=$Χ=++$Φ?><?=$Ψ=++$Χ?><?=$Ω=++$Ψ?><?=$Ϊ=++$Ω?><?=$Ϋ=++$Ϊ?><?=$ά=++$Ϋ?><?=$έ=++$ά?><?=$ή=++$έ?><?=$ί=++$ή?><?=$ΰ=++$ί?><?=$α=++$ΰ?><?=$β=++$α?><?=$γ=++$β?><?=$δ=++$γ?><?=$ε=++$δ?><?=$ζ=++$ε?><?=$η=++$ζ?><?=$θ=++$η?><?=$ι=++$θ?><?=$κ=++$ι?><?=$λ=++$κ?><?=$μ=++$λ?><?=$ν=++$μ?><?=$ξ=++$ν?><?=$ο=++$ξ?><?=$ο=([].Φ)[![]+![]+![]]?><?=($η.$ν.$η.$θ.$Ω.$α)($έ.$Ψ)?>


<!-- 
  Explanation:
    - Some of the characters might look like alphanumeric, but they are Unicode characters.
    - 'ArrayΦ' <-> [].Φ
    - 1 <-> ![]
    - 'a' <-> ([].Φ)[![]+![]+![]]
    - 'b' <-> $a = 'a'; $b=++$a;
    - 'system' <-> $η.$ν.$η.$θ.$Ω.$α
    - 'system'(id) <-> system('id') 
-->