$re = '/.*powershell\.exe.*\-[Ee^]{1,2}[NnCcOoDdEeMmAa^]*\s*[A-Za-z0-9+\/=]{5,}/m';
$str = 'powershell.exe -encodedCommand JwBtAGkAawBlAGYAcgBvAGIAYgBpAG4AcwAuAGMAbwBtACcA
powershell.exe -Enc JwBtAGkAawBlAGYAcgBvAGIAYgBpAG4AcwAuAGMAbwBtACcA
powershell.exe -e JwBtAGkAawBlAGYAcgBvAGIAYgBpAG4AcwAuAGMAbwBtACcA
powershell.exe -w Hidden -ENC JwBtAGkAawBlAGYAcgBvAGIAYgBpAG4AcwAuAGMAbwBtACcA
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php