JRAT - layer 1 decryptor

b.java

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.GZIPInputStream;

public class b {
    public static byte[] a(byte[] inp) throws IOException {
        int n;
        GZIPInputStream a2 = new GZIPInputStream(new ByteArrayInputStream((byte[])inp));
        byte[] arrby = new byte[1024];
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        byte[] arrby2 = arrby;
        while ((n = a2.read(arrby2)) >= 0) {
            byte[] arrby3 = arrby;
            arrby2 = arrby3;
            byteArrayOutputStream.write(arrby3, 0, n);
        }
        a2.close();
        ByteArrayOutputStream byteArrayOutputStream2 = byteArrayOutputStream;
        byteArrayOutputStream2.close();
        return byteArrayOutputStream2.toByteArray();
    }
}

c.java

import java.security.Key;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

public final class c {
    public static String a(String a2) {
        int n;
        int n2 = a2.length();
        int n3 = n = n2 - 1;
        char[] arrc = new char[n2];
        while (n3 >= 0) {
            int n4 = n--;
            arrc[n4] = (char)(a2.charAt(n4) ^ 49);
            if (n < 0) break;
            int n5 = n--;
            arrc[n5] = (char)(a2.charAt(n5) ^ 58);
            n3 = n;
        }
        return new String(arrc);
    }

    public static byte[] a(byte[] a2, byte[] a3) {
        try {
            Key key = new SecretKeySpec((byte[])a3, "AES");
            Cipher cipher2 = Cipher.getInstance("AES/ECB/PKCS5Padding");
            cipher2.init(2, key);
            a2 = cipher2.doFinal(a2);
            return a2;
        }
        catch (Exception v1) {
            return null;
        }
    }
}

main.java

import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;

import java.io.IOException;
import java.io.InputStream;
import java.security.GeneralSecurityException;

public class main {
	
    public static byte[] readFromStream(InputStream param1) throws IOException {
        int n;
        ByteArrayOutputStream kyqa2 = new ByteArrayOutputStream();
        byte[] arrby = new byte[2048];
        InputStream inputStream = param1;
        while ((n = inputStream.read(arrby)) > -1) {
            inputStream = param1;
            kyqa2.write(arrby, 0, n);
        }
        ByteArrayOutputStream kyqa3 = kyqa2;
        kyqa3.close();
        return kyqa3.toByteArray();
    }

    public static byte[] decrypt(String encData, String aesKey, String outFile) throws IOException, ClassNotFoundException, GeneralSecurityException
    {
        byte[] inpData = readFromStream(new FileInputStream(encData));
        byte[] decrypted = b.a(c.a(inpData, aesKey.getBytes()));
        
        FileOutputStream fos = new FileOutputStream(outFile);
        fos.write(decrypted);
        fos.close();
        return decrypted;
    }
    
    public static void main(String[] args) throws IOException, ClassNotFoundException, GeneralSecurityException
    {	
        if (args.length < 4) {
            System.out.println("Args: <encData> <aesKey> <outFile>");
            return;
        }
        decrypt(args[0], args[1], args[2]);
    }
}