Cyber Anakins Lightsaber - A Minishell-based backdoor

######################################################################
#                    MAIN CONFIGURATION SETTINGS                     #
######################################################################

RELAY = 10.3.225.25
USER = bjb2293782

exim_user = USER
exim_group = USER

pid_file_path = /var/run/exim.pid
queue_run_max = 1
remote_max_parallel = 1

domainlist local_domains = @
domainlist relay_to_domains =

keep_environment =
add_environment =

acl_smtp_rcpt = acl_check_rcpt
acl_not_smtp = acl_check_localgen_messages

never_users = root
rfc1413_hosts = *
rfc1413_query_timeout = 30s
recipient_unqualified_hosts = RELAY

ignore_bounce_errors_after = 0d
timeout_frozen_after = 3d
local_from_check=false

log_selector = +all

FILE_COUNT_QUEUE=/etc/exim/queue_size
MAX_QUEUE_SIZE=31000

######################################################################
#                   PERFORMANCE CONFIGURATION                        #
######################################################################

queue_only_load = 100.0
deliver_queue_load_max = 100.0
message_size_limit = 30M
recipients_max = 25
received_headers_max = 20

######################################################################
#                       ACL CONFIGURATION                            #
#         Specifies access control lists for incoming SMTP mail      #
######################################################################

begin acl

acl_check_localgen_messages:

  warn set acl_m_queue_size=${if exists{FILE_COUNT_QUEUE} {${readfile{FILE_COUNT_QUEUE}{}}}{0}}

  discard message = There are too many messages [$acl_m_queue_size] in the mail queue
                condition = ${if >={$acl_m_queue_size}{MAX_QUEUE_SIZE}}

accept

acl_check_rcpt:

  deny    message       = Restricted characters in address
          domains       = +local_domains
          local_parts   = ^[.] : ^.*[@%!/|]

  deny    message       = Restricted characters in address
          domains       = !+local_domains
          local_parts   = ^[./|] : ^.*[@%!] : ^.*/\\.\\./

  accept  local_parts   = postmaster
          domains       = +local_domains

  accept  domains       = +local_domains
          endpass
          verify        = recipient

  accept  domains       = +relay_to_domains
          endpass
          verify        = recipient

  # Reaching the end of the ACL causes a "deny", but we might as well give
  # an explicit message.

  deny    message       = relay not permitted

######################################################################
#                      ROUTERS CONFIGURATION                         #
#               Specifies how addresses are handled                  #
######################################################################
#     THE ORDER IN WHICH THE ROUTERS ARE DEFINED IS IMPORTANT!       #
# An address is passed to each router in turn until it is accepted.  #
######################################################################

begin routers

external:
  driver = manualroute
  transport = remote_smtp
  route_data = RELAY
  no_more

# The remaining routers handle addresses in the local domain(s).

system_aliases:
  driver = redirect
  allow_fail
  allow_defer
  data = ${lookup{$local_part}lsearch{/etc/aliases}}
  file_transport = address_file
  pipe_transport = address_pipe

userforward:
  driver = redirect
  user = USER
  check_local_user
  file = $home/.forward
  no_verify
  no_expn
  check_ancestor
  file_transport = address_file
  pipe_transport = address_pipe
  reply_transport = address_reply

localuser:
  driver = accept
  user = USER
  transport = local_delivery
  cannot_route_message = Unknown user

######################################################################
#                      TRANSPORTS CONFIGURATION                      #
######################################################################
#                       ORDER DOES NOT MATTER                        #
#     Only one appropriate transport is called for each delivery.    #
######################################################################

begin transports

remote_smtp:
  driver = smtp
  max_rcpt = 1
  message_linelength_limit = 8192

local_delivery:
  driver = appendfile
  file = /dev/null

address_pipe:
  driver = pipe
  return_output

address_file:
  driver = appendfile
  delivery_date_add
  envelope_to_add
  return_path_add

address_reply:
  driver = autoreply

######################################################################
#                      RETRY CONFIGURATION                           #
######################################################################

begin retry

# This single retry rule applies to all domains and all errors. It specifies
# retries every 15 minutes for 2 hours, then increasing retry intervals,
# starting at 1 hour and increasing each time by a factor of 1.5, up to 16
# hours, then retries every 6 hours until 4 days have passed since the first
# failed delivery.

# Address or Domain    Error       Retries
# -----------------    -----       -------

*                      *           F,2h,5m; G,16h,1h,1.5; F,7d,6h

######################################################################
#                      REWRITE CONFIGURATION                         #
######################################################################

begin rewrite

*@$primary_hostname postmaster@$primary_hostname Ffsr
USER@$primary_hostname postmaster@$primary_hostname Tt

#.include /etc/mail/out.conf

######################################################################
#                   AUTHENTICATION CONFIGURATION                     #
######################################################################

# There are no authenticator specifications in this default configuration file.

begin authenticators

######################################################################
#                   CONFIGURATION FOR local_scan()                   #
######################################################################

# If you have built Exim to include a local_scan() function that contains
# tables for private options, you can define those options here. Remember to
# uncomment the "begin" line. It is commented by default because it provokes
# an error with Exim binaries that are not built with LOCAL_SCAN_HAS_OPTIONS
# set in the Local/Makefile.

# begin local_scan


# End of Exim configuration file