Tags: forensics 

Rating:

```powershell
$enc = [System.Text.Encoding]::ASCII

function encr {
param(
[Byte[]]$data,
[Byte[]]$key
)

[Byte[]]$buffer = New-Object Byte[] $data.Length
$data.CopyTo($buffer, 0)

[Byte[]]$s = New-Object Byte[] 256;
[Byte[]]$k = New-Object Byte[] 256;

for ($i = 0; $i -lt 256; $i++)
{
$s[$i] = [Byte]$i;
$k[$i] = $key[$i % $key.Length];
}

$j = 0;
for ($i = 0; $i -lt 256; $i++)
{
$j = ($j + $s[$i] + $k[$i]) % 256;
$temp = $s[$i];
$s[$i] = $s[$j];
$s[$j] = $temp;
}

$i = $j = 0;
for ($x = 0; $x -lt $buffer.Length; $x++)
{
$i = ($i + 1) % 256;
$j = ($j + $s[$i]) % 256;
$temp = $s[$i];
$s[$i] = $s[$j];
$s[$j] = $temp;
[int]$t = ($s[$i] + $s[$j]) % 256;
$buffer[$x] = $buffer[$x] -bxor $s[$t];
}

return $buffer
}

function HexToBin {
param(
[Parameter(
Position=0,
Mandatory=$true,
ValueFromPipeline=$true)
]
[string]$s)
$return = @()

for ($i = 0; $i -lt $s.Length ; $i += 2)
{
$return += [Byte]::Parse($s.Substring($i, 2), [System.Globalization.NumberStyles]::HexNumber)
}

Write-Output $return
}

[Byte[]]$key = $enc.GetBytes("Q0mmpr4B5rvZi3pS");
$encrypted1 = "F844A6035CF27CC4C90DFEAF579398BE6F7D5ED10270BD12A661DAD04191347559B82ED546015B07317000D8909939A4DA7953AED8B83C0FEE4EB6E120372F536BC5DC39"
$encrypted2 = "CC19F66A5F3B2E36C9B810FE7CC4D9CE342E8E00138A4F7F5CDD9EED9E09299DD7C6933CF4734E12A906FD9CE1CA57D445DB9CABF850529F5845083F34BA1"
$encrypted3 = "C08114AA67EB979D36DC3EFA0F62086B947F672BD8F966305A98EF93AA39076C3726B0EDEBFA10811A15F1CF1BEFC78AFC5E08AD8CACDB323F44B4D"
$encrypted4 = "D814EB4E244A153AF8FAA1121A5CCFD0FEAC8DD96A9B31CCF6C3E3E03C1E93626DF5B3E0B141467116CC08F92147F7A0BE0D95B0172A7F34922D6C236BC7DE54D8ACBFA70D1"
$encrypted5 = "84AB553E67C743BE696A0AC80C16E2B354C2AE7918EE08A0A3887875C83E44ACA7393F1C579EE41BCB7D336CAF8695266839907F47775F89C1F170562A6B0A01C0F3BC4CB"
$encrypted = "$($encrypted1)$($encrypted2)$($encrypted3)$($encrypted4)$($encrypted5)"

[Byte[]]$data = HexToBin $encrypted
$DecryptedBytes = encr $data $key
$DecryptedString = $enc.GetString($DecryptedBytes)
$DecryptedString

#HTB{g0ld3n_F4ng_1s_n0t_st34lthy_3n0ugh}
```