HACKER defender finder

# SPDX-FileCopyrightText: 2004 SIA
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-only

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.15517");
  script_version("2026-06-11T07:15:11+0000");
  script_tag(name:"last_modification", value:"2026-06-11 07:15:11 +0000 (Thu, 11 Jun 2026)");
  script_tag(name:"creation_date", value:"2005-11-03 14:08:04 +0100 (Thu, 03 Nov 2005)");
  script_tag(name:"cvss_base", value:"10.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:C/I:C/A:C");
  script_name("HACKER defender finder");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2004 SIA");
  script_family("Malware");
  script_dependencies("find_service.nasl", "os_detection.nasl");
  script_mandatory_keys("Host/runs_windows");
  script_require_ports(7, 21, 25, 80, 443, 1025, 3389);

  script_tag(name:"solution", value:"Reinstall Windows.");

  script_tag(name:"summary", value:"This script checks whether the remote host is running the Hacker
  Defender backdoor.");

  script_tag(name:"insight", value:"Hacker Defender is a rootkit for Windows. Among other things, it hooks
  itself into all open TCP ports on the system, listening for a specially-crafted packet, and opening a
  backdoor on that port when found. This backdoor can be used by malicious users to control the
  affected host remotely.");

  script_tag(name:"qod_type", value:"remote_active");
  script_tag(name:"solution_type", value:"Mitigation");

  exit(0);
}

include("host_details.inc");

list_ports[0] = 80;
list_ports[1] = 3389;
list_ports[2] = 21;
list_ports[3] = 25;
list_ports[4] = 7;
list_ports[5] = 1025;
list_ports[6] = 443;

max_ports = 6;

hx[0]=raw_string (0x01, 0x1e, 0x3c, 0x6c, 0x6a, 0xff, 0x99, 0xa8,0x34, 0x83, 0x38, 0x24, 0xa1, 0xa4, 0xf2, 0x11,0x5a, 0xd3, 0x18, 0x8d, 0xbc, 0xc4, 0x3e, 0x40,0x07, 0xa4, 0x28, 0xd4, 0x18, 0x48, 0xfe, 0x00);
hx_banner[0] = string("Hacker Defender v0.51-0.82b");

hx[1]=raw_string(0x01, 0x38, 0x45, 0x69, 0x3a, 0x1f, 0x44, 0x12,0x89, 0x55, 0x7f, 0xaa, 0xc0, 0x9f, 0xee, 0x61,0x3f, 0x9a, 0x7e, 0x84, 0x32, 0x04, 0x4e, 0x1d,0xd7, 0xe4, 0xa8, 0xc4, 0x48, 0xe8, 0x9e, 0x00);
hx_banner[1] = string("Hacker Defender v0.82-0.83");

hx[2]=raw_string(0x01, 0x9a, 0x8c, 0x66, 0xaf, 0xc0, 0x4a, 0x11,0x9e, 0x3f, 0x40, 0x88, 0x12, 0x2c, 0x3a, 0x4a,0x84, 0x65, 0x38, 0xb0, 0xb4, 0x08, 0x0b, 0xaf,0xdb, 0xce, 0x02, 0x94, 0x34, 0x5f, 0x22, 0x00);
hx_banner[2] = string("Hacker Defender v0.84-1.0.0");


for (i=0; i <= max_ports; i++) {

  if (get_port_state(list_ports[i]))
  {
    soc = open_sock_tcp (list_ports[i]);
    if (soc)
    {
      for (j=0;j<3;j++) {
        # nb: to understand this, look at the HandlerRoutine in
        #     bdcli100.dpr in the Hacker Defender source.
        send (socket:soc, data: hx[j]);
        data = recv (socket:soc, length:128, timeout:1);
        if (data && strlen(data) == 1 && ord(data[0]) == 0xe0)
        {
          for (t=0; t<20; t++) {
            send (socket:soc, data: raw_string(0xe1));
            data = recv (socket:soc, length:1, timeout:1);
            if (data && strlen(data) == 1 && ord(data[0]) == 0xe2)
            {
              report = string("The remote host is running the ", hx_banner[j], " backdoor.");
              security_message(data:report, port:list_ports[i]);
              exit(0);
            }
          }
        }
      }
      close(soc);
    }
  }
}