unhide.rb/ 0000755 0001750 0001750 00000000000 12107506243 012272 5 ustar julien julien unhide.rb/unhide.rb.8 0000644 0001750 0001750 00000002254 12107505157 014247 0 ustar julien julien .TH unhide.rb 8 "March 2011" "" "unhide.rb - Finder of hidden processes"
.SH NAME
unhide.rb - Scans system for hidden processes and lists any hits on stderr.
.SH SYNOPSIS
.B unhide.rb
.br
.SH DESCRIPTION
Scans the system for hidden processes.
.PP
Progress messages are printed on stdout and can be redirected to
/dev/null.
.PP
Error diagnostics and information about any hidden processes found is
printed to stderr.
.SH OPTIONS
unhide.rb takes no options
.SH "EXIT STATUS"
.TP
0
No hidden processes found
.TP
1
Something went wrong during scanning
.TP
2
One or more hidden processes were detected
.SH BUGS
Report bugs to
.RB < johan.walles@gmail.com >
or
.RB < https://bugs.launchpad.net/unhide.rb >.
.SH LICENSING
unhide.rb is licensed under the GPL-3, copyright Johan Walles
.RB < johan.walles@gmail.com >.
.SH "SEE ALSO"
rkhunter(8)
.PP
The unhide.rb home page:
.RB < http://launchpad.net/unhide.rb >
.SH NOTES
unhide.rb is a Ruby port of unhide. When it was first written, the
Ruby port was about 10x faster than the original C program and had
much better diagnostics when hidden processes were found. The
original unhide program can be found at
.RB < http://www.unhide-forensics.info/ >.
unhide.rb/unhide.rb 0000755 0001750 0001750 00000033707 12107505157 014113 0 ustar julien julien #!/usr/bin/ruby -w
# Try to find running processes using different methods, and report
# processes found through some means but not through others.
#
# Exit code 2 means something fishy was detected.
#
# Exit code 1 means something went wrong.
# Copyright 2009 by Johan Walles, johan.walles@gmail.com
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see .
require 'set'
require 'dl/import'
require 'dl/struct'
# Support for libc functions not covered by the standard Ruby
# libraries
module LibC
if RUBY_VERSION =~ /^1\.8/
extend DL::Importable
else
extend DL::Importer
end
dlload "libc.so.6"
# PID scanning functions
extern "int getsid(int)"
extern "int sched_getscheduler(int)"
extern "int sched_getparam(int, void*)"
extern "int sched_rr_get_interval(int, void*)"
extern "int sched_getaffinity(int, int, void*)"
extern "int readlink(char *, char *, int)"
extern "int kill(int, int)"
# We want to ask sysinfo about the number of active PIDs. This
# result struct has been taken from the sysinfo(2) Linux man page.
SysInfoData = struct [
"long uptime",
"long loads[3]",
"long totalram",
"long freeram",
"long sharedram",
"long bufferram",
"long totalswap",
"long freeswap",
"short procs",
"long padding[42]"
]
extern "int sysinfo(void *)"
end
# A piece of scratch memory where system calls can fill in
# information. What's written here is not interesting, it's just that
# some of the PID scanning functions need a memory area to write into.
scratch = "\0" * 1024
# Make sure our scratch buffer is large enough for sched_getaffinity()
while LibC.sched_getaffinity(0, scratch.length, scratch) == -1
scratch = "\0" * (scratch.length * 2)
end
$proc_parent_pids = nil
$proc_tasks = nil
$ps_pids = nil
$proc_readdir_pids = nil
def setup
# List all parent processes pointed out by anybody in /proc
$proc_parent_pids = Set.new
proc_dir = Dir.new("/proc")
proc_dir.each do |proc_entry|
next unless File.directory?("/proc/" + proc_entry)
next unless proc_entry =~ /^[0-9]+$/
status_file = File.new("/proc/#{proc_entry}/status")
begin
status_file.each_line do |line|
line.chomp!
next unless line =~ /^ppid:\s+([0-9]+)$/i
ppid = $1.to_i
$proc_parent_pids << ppid
break
end
ensure
status_file.close
end
end
proc_dir.close
# List all thread pids in /proc
$proc_tasks = {}
proc_dir = Dir.new("/proc")
proc_dir.each do |proc_entry|
next unless File.directory?("/proc/" + proc_entry)
next unless proc_entry =~ /^[0-9]+$/
task_dir = Dir.new("/proc/#{proc_entry}/task")
begin
task_dir.each do |task_pid|
next unless task_pid =~ /^[0-9]+$/
# "true" means we *have* an executable
exe = true
begin
# Store the *name* of the executable
exe = File.readlink("/proc/#{proc_entry}/task/#{task_pid}/exe")
rescue Errno::EACCES, Errno::ENOENT
# This block intentionally left blank
end
$proc_tasks[task_pid.to_i] = exe
end
ensure
task_dir.close
end
end
proc_dir.close
# List all PIDs displayed by ps
$ps_pids = {}
$ps_pids.default = false
ps_stdout = IO.popen("ps axHo lwp,cmd", "r")
ps_pid = ps_stdout.pid
ps_stdout.each_line do |ps_line|
ps_line.chomp!
next unless ps_line =~ /^\s*([0-9]+)\s+([^ ]+).*$/
pid = $1.to_i
exe = $2
$ps_pids[pid] = exe
end
ps_stdout.close
# Remove the ps process itself from our pid list
$ps_pids.delete ps_pid
# List all pids found by readdir on /proc
$proc_readdir_pids = Set.new
Dir.open("/proc").each do |dir|
next unless dir =~ /^[0-9]+$/
$proc_readdir_pids << dir.to_i
end
end
# Return errno after last library call
def get_errno()
return DL.respond_to?("last_error") ? DL::last_error : Fiddle::last_error
end
# This array contains named PID detectors. Given a PID to examine they
# can say:
# * true (it exists)
# * "some string" (it exists, and here is its name)
# * false (it doesn't exist)
# * nil (don't know)
$pid_detectors = [
["ps", proc { |pid|
# Does "ps" list this pid?
$ps_pids[pid]
}],
["/proc naive", lambda { |pid|
# Is there a /proc entry for this pid?
File.directory?("/proc/#{pid}")
}],
["/proc readdir", lambda { |pid|
# Did we find this pid when listing the contents of /proc?
if $proc_readdir_pids.include?(pid)
true
else
nil
end
}],
["/proc opendir", lambda { |pid|
# Is there a /proc entry for this pid that we can do opendir() on?
begin
Dir.open("/proc/#{pid}")
true
rescue Errno::ENOENT
false
end
}],
["/proc//status", lambda { |pid|
# Parse the process name out of /proc/1234/status
begin
process_name = true
File.open("/proc/#{pid}/status").each do |line|
next unless line =~ /Name:[\t ]+(.*)$/
process_name = $1
break
end
process_name
rescue Errno::ENOENT
false
end
}],
["/proc readlink", lambda { |pid|
# Read the /proc/1234/exe entry for this pid
begin
File.readlink("/proc/#{pid}/exe")
rescue Errno::EACCES
""
rescue Errno::ENOENT
# Some kernel processes have unreadable symlinks in /proc/1234/pid, and
# we can't tell "unreadable symlink" apart from "process doesn't exist"
nil
end
}],
["/proc libc-readlink", lambda { |pid|
# Is this process visible by the readlink libc function?
# The result of this can differ from File.readlink() if
# somebody has preloaded a library that overrides certain
# libc functions as described here:
# http://sourceforge.net/mailarchive/message.php?msg_id=28258660
length = LibC.readlink("/proc/#{pid}/exe", scratch, scratch.length)
if length >= 0
scratch[0..(length - 1)]
else
case get_errno()
when 2 # ENOENT
# Some kernel processes have unreadable symlinks in /proc/1234/pid, and
# we can't tell "unreadable symlink" apart from "process doesn't exist"
nil
when 13 # EACCES
""
else
raise "Unknown errno #{errno}"
end
end
}],
["/proc tasks", proc { |pid|
# Is there a /proc/1234/tasks/pid directory for
# this pid?
$proc_tasks[pid]
}],
["/proc parent", proc { |pid|
# Does any /proc entry point this pid out as a
# parent pid?
if $proc_parent_pids.include? pid
true
else
nil
end
}],
["/proc chdir", proc { |pid|
# Can we chdir into /proc/?
begin
Dir::chdir "/proc/#{pid}"
true
rescue Errno::ENOENT
false
end
}],
["getsid()", proc { |pid|
LibC.getsid(pid) != -1
}],
["getpgid()", proc { |pid|
exists = true
begin
Process.getpgid(pid)
rescue
exists = false
end
exists
}],
["getpriority()", proc { |pid|
exists = true
begin
Process.getpriority(Process::PRIO_PROCESS, pid)
rescue
exists = false
end
exists
}],
["sched_getparam()", proc { |pid|
LibC.sched_getparam(pid, scratch) != -1
}],
["sched_getaffinity()", proc { |pid|
LibC.sched_getaffinity(pid, scratch.length, scratch) != -1
}],
["sched_getscheduler()", proc { |pid|
LibC.sched_getscheduler(pid) != -1
}],
["kill(pid, 0)", proc { |pid|
if LibC.kill(pid, 0) == 0
true
else
case get_errno
when 1 # EPERM
true
when 3 # ESRCH
false
else
raise "Unknown errno #{errno}"
end
end
}]
]
found_something = false
# Scan PIDs and report those found by some means but not others
#
# Returns a map of pids->warning strings
def get_suspicious_pids(pids_to_scan = nil)
if pids_to_scan == nil
pid_max = File.new("/proc/sys/kernel/pid_max").gets.to_i
pids_to_scan = (1..pid_max)
end
return_me = Hash.new
pids_to_scan.each do |pid|
pid_exists = {}
$pid_detectors.each do |pid_detector|
detector_name = pid_detector[0]
detector_proc = pid_detector[1]
pid_exists[detector_name] = detector_proc.call(pid)
end
# Is there consensus about the existence of this process?
suspicious = false
existence_consensus = nil
pid_exists.values.each do |existence|
# Always over-write "don't know"
existence_consensus = existence if existence_consensus == nil
# This one is undecisive, skip it
next if existence == nil
# Does the result of this test match the consensus?
if existence_consensus == false
unless existence == false
suspicious = true
break
end
else
# Anything but "false" is considered to be true, can be a string
# with a process name in it for example
if existence == false
suspicious = true
break
end
end
end
if suspicious
# Put output in a string and add it to the return result
message = "Suspicious PID #{pid}:"
$pid_detectors.each do |detector|
detector_name = detector[0]
detector_result = pid_exists[detector_name]
next if detector_result == nil
description = ""
description =
" (\"#{detector_result}\")" if detector_result.class == String
message +=
sprintf("\n %s: %s%s",
detector_result ? " Seen by" : "Invisible to",
detector_name,
description)
end
return_me[pid] = message
end
end
return return_me
end
##
## Main program starts here
##
puts "Scanning for hidden processes..."
setup
# Check for unknown preloads. This will name the Jynx LD Poisoning
# library.
suspicious_mappings = Set.new
File.open("/proc/self/maps").each do |line|
next unless line =~ /[^\/]*(\/.*)$/
mapped_file = $1
next if File::exist? mapped_file
suspicious_mappings << mapped_file
end
unless suspicious_mappings.empty?
found_something = true
STDERR.puts "I have a mapped file (or more) that I can't access! Results may be wrong."
STDERR.puts "Check /etc/ld.so.preload or dynamic linker for compromise:"
suspicious_mappings.each do |mapping|
STDERR.puts " #{mapping}"
end
end
# Verify PID count between ps and sysinfo()
sysinfo = LibC::SysInfoData.malloc
if LibC.sysinfo(sysinfo) == -1
STDERR.puts "Error: failed calling sysinfo()"
exit 1
end
if sysinfo.procs != $ps_pids.size
$stderr.puts "ps and sysinfo() process count mismatch:"
$stderr.puts " ps: #{$ps_pids.size} processes"
$stderr.puts " sysinfo(): #{sysinfo.procs} processes"
found_something = true
end
suspicious_pids = get_suspicious_pids
unless suspicious_pids.empty?
# Filter out false positives by testing all positives again. False
# positives occur when we race with processes starting up or
# shutting down.
setup
still_suspicious_pids = get_suspicious_pids(suspicious_pids.keys)
still_suspicious_pids.keys.sort.each do |still_suspicious_pid|
warning_text = suspicious_pids[still_suspicious_pid]
next unless warning_text
found_something = true
$stderr.puts warning_text
end
end
if found_something
exit 2
else
puts "No hidden processes found!"
end
unhide.rb/Makefile 0000644 0001750 0001750 00000000254 12107505157 013736 0 ustar julien julien PREFIX=/usr
all :
@echo Nothing to do for all, try \"make install\".
install :
install unhide.rb ${PREFIX}/bin
install --mode=644 unhide.rb.8 ${PREFIX}/share/man/man8