Bilgi Bankası

Maldet nedir ? Maldet Linux sunucularda zararlı Shell yazılımlarına karşı davranış sergileyen yazılımdır. Maldet ile bir sunucu üzerinde kapsamlı tarama veya kullanıcı taraması yapabilirsiniz.
Maldet kurulumu ise aşağıdaki şekildedir.

wget http://www.rfxn.com/downloads/maldetect-current.tar.gz
tar zxvf maldetect-current.tar.gz
cd maldet*
sh install.sh

Kurulum bittikten sonra ayarlarını yapmak için

/usr/local/maldetect/conf.maldet

dosyasını herhangi bir editör yardımıyla açıp dosyayı kendinize göre ayarlamalısınız. İsterseniz bizim düzenlemiş olduğumuz config dosyasını kopyalayıp kullanabilirsiniz.

#!/bin/bash
#
##
# Linux Malware Detect v1.5
#             (C) 2002-2014, R-fx Networks <proj@r-fx.org>
#             (C) 2014, Ryan MacDonald <ryan@r-fx.org>
# This program may be freely redistributed under the terms of the GNU GPL v2
##
#
##
# [ General Options ]
##

# Enable or disable e-mail alerts, this includes application version
# alerts as well as automated/manual scan reports. On-demand reports
# can still be sent using '--report SCANID user@domain.com'.
# [0 = disabled, 1 = enabled]
email_alert="1"

# The destination e-mail addresses for automated/manual scan reports
# and application version alerts.
# [ multiple addresses comma (,) spaced ]
email_addr="root@alicomez.com"

# Ignore e-mail alerts for scan reports in which all malware hits
# have been automatically and successfully cleaned.
# [0 = disabled, 1 = enabled]
email_ignore_clean="1"

# This controls the daily automatic updates of LMD signature files
# and cleaner rules. The signature update process preserves any
# custom signature or cleaner files. It is highly recommended that this
# be enabled as new signatures a released multiple times per-week.
# [0 = disabled, 1 = enabled]
autoupdate_signatures="1"

# This controls the daily automatic updates of the LMD installation.
# The installation update process preserves all configuration options
# along with custom signature and cleaner files. It is recommended that
# this be enabled to ensure the latest version, features and bug fixes
# are always available.
# [0 = disabled, 1 = enabled]
autoupdate_version="1"

# This controls validating the LMD executable MD5 hash with known
# good upstream hash value. This allows LMD to replace the the
# executable / force a reinstalltion in the event the LMD executable
# is tampered with or corrupted. If you intend to make customizations
# to the LMD executable, you should disable this feature.
# [0 = disabled, 1 = enabled]
autoupdate_version_hashed="1"

# When defined, the import_config_url option allows a configuration file to be
# downloaded from a remote URL. The local conf.maldet and internals.conf are
# parsed followed by the imported configuration file. As such, only variables
# defined in the imported configuration file are overridden and a full set of
# configuration options is not explicitly required in the imported file.
# [ some IP use dns caption recommendation goes here ]
import_config_url=""

# When defined, the import_custsigs_*_url options allow for the custom signature
# files to be downloaded from a remote URL. THIS WILL OVERWRITE ANY LOCAL CUSTOM
# SIGNATURE FILES! It is recommended for large-scale deployments to define these
# variables within a import_config_url file.
# [ some IP use dns caption recommendation goes here ]
import_custsigs_md5_url=""
import_custsigs_hex_url=""

##
# [ SCAN OPTIONS ]
##

# The maximum directory depth that the scanner will search, a value
# of 15 is recommended.
# [ changing this may have an impact on scan performance ]
scan_max_depth="15"

# The minimum file size in bytes for a file to be included in LMD scans.
# [ changing this may have an impact on scan performance ]
scan_min_filesize="24"

# The maximum file size for a file to be included in LMD scans. Accepted
# value formats are b, k, M. When using the clamscan engine, the max_filesize
# will be dynamically set based on the largest known filesize from the MD5
# hash signature file.
# [ changing this may have an impact on scan performance ]
scan_max_filesize="2048k"

# The maximum byte depth that the scanner will search into a files content.
# The default signature rules expect a depth size of at least 65536 bytes.
# [ changing this may have an impact on scan performance ]
scan_hexdepth="65536"

# Use named pipe (FIFO) for passing file contents hex data instead of stdin
# default; improved performance and greater scanning depth. This is highly
# recommended and works on most systems. The hexfifo will be disabled
# automatically if for any reason it can not be successfully utilized.
# [ 0 = disabled, 1 = enabled ]
scan_hexfifo="1"

# The maximum byte depth that the scanner will search into a files content
#s when using named pipe (FIFO). Improved performance allows for greater
# scan depth over default scan_hexdepth value.
# [ changing this may have an impact on scan performance ]
scan_hexfifo_depth="524288"

# If installed, use ClamAV clamscan binary as default scan engine which
# provides improved scan performance on large file sets. The clamscan
# engine is used in conjunction with native ClamAV signatures updated
# through freshclam along with LMD signatures providing additional
# detection capabilities.
# [ 0 = disabled, 1 = enabled ]
scan_clamscan="1"

# Include the scanning of known temporary world-writable paths for
# -a|--al and -r|--recent scan types.
scan_tmpdir_paths="/tmp /var/tmp /dev/shm"

# Allows non-root users to perform scans. This must be enabled when
# using mod_security2 upload scanning or if you want to allow users
# to perform scans. When enabled, this will populate 'pub/' with user
# owned quarantine, session and temporary paths to faciliate scans.
# [ 0 = disabled, 1 = enabled, disabled by default ]
scan_user_access="0"

# Process CPU scheduling (nice) priority level for scan operations.
# [ -19 = high prio , 19 = low prio, default = 19 ]
scan_cpunice="19"

# Process IO scheduling (ionice) priority levels for scan operations.
# (uses cbq best-effort scheduling class [-c2])
# [ 0 = most favorable IO, 7 = least favorable IO ]
scan_ionice="6"

# Set hard limit on CPU usage for find and clam(d)scan processes. This
# requires the 'cpulimit' binary to be available on the server. The values
# are expressed as relative percentage * N cores on system. An 8 CPU core
# server would accept values from 0 - 800, 12 cores 0 - 1200 etc...
scan_cpulimit="0"

# As a design and common use case, LMD typically only scans user space paths
# and as such it makes sense to ignore files that are root owned. It is
# recommended to leave this enabled for best performance.
# [ 0 = disabled, 1 = enabled ]
scan_ignore_root="1"

# This allows for specific user or groups to be ignored entirely from scan
# file lists. This option should be used with care and is not ideal for
# ignoring false positives. Instead, you should use one of the ignore files,
# such as ignore_paths, to exclude a specific file name or path from scans.
# [ comma or white spaced list of user and group names ]
scan_ignore_user=""
scan_ignore_group=""

# The maximum amount of time, in seconds, that the 'find' file list generation
# will run before it is terminated. All 'find' results up to the point of
# termination will be fully scanned. If performing a full scan of all user paths
# on a large server, it is reasonable to expect the find operation may take a
# long time to complete and as such this feature may interfere. In such cases,
# this feature can be disabled/modified on a per-scan basis using the
# '-co|--config-option' CLI option, such as:
# "maldet -co scan_find_timeout=0 -a /home/?/public_html".
# [ 0 = disabled, 14400 = 4hr recommended timeout ]
scan_find_timeout="0"

# The daily cron 'find' operation performed by LMD detects recently created/modifed
# user files. This 'find' operation can be especially resource intensive and it may
# be desirable to persist the file list results so that other applications/tasks
# may make use of the results. When scan_export_filelist is set enabled, the most
# recent result set will be saved to '/usr/local/maldetect/tmp/find_results.last'
# [ 0 = disabled, 1 = enabled ]
scan_export_filelist="0"

##
# [ QUARANTINE OPTIONS ]
##
# The default quarantine action for malware hits
# [0 = alert only, 1 = move to quarantine & alert]
quarantine_hits="1"

# Try to clean string based malware injections
# [NOTE: quarantine_hits=1 required]
# [0 = disabled, 1 = clean]
quarantine_clean="1"

# The default suspend action for users wih hits
# Cpanel suspend or set shell /bin/false on non-Cpanel
# [NOTE: quarantine_hits=1 required]
# [0 = disabled, 1 = suspend account]
quarantine_suspend_user="1"

# The minimum userid value that can be suspended
# [ default = 500 ]
quarantine_suspend_user_minuid="500"

##
# [ MONITORING OPTIONS ]
##
# The base number of files that can be watched under a path
# [ maximum file watches = inotify_base_watches*users ]
inotify_base_watches="16384"

# The sleep time in seconds between monitor runs to scan files
# that have been created/modified/moved
inotify_sleep="30"

# The interval in seconds that inotify will reload configuration
# data, including remote configuration imports.
inotify_reloadtime="3600"

# The minimum userid that will be added to path monitoring when
# the USERS option is specified
inotify_minuid="500"

# This is the html/web root for users relative to homedir, when
# this option is set, users will only have the webdir monitored
# [ clear option to default monitor entire user homedir ]
inotify_docroot="public_html"

# Process CPU scheduling (nice) priority level for monitoring process.
# [ -19 = high prio , 19 = low prio, default = 15 ]
inotify_cpunice="18"

# Process IO scheduling (ionice) priority levels for scan operations.
# (uses cbq best-effort scheduling class [-c2])
# [ 0 = most favorable IO, 7 = least favorable IO ]
inotify_ionice="6"

# Set hard limit on CPU usage for inotify monitoring processes. This requires
# the 'cpulimit' binary to be available on the server. The values are expressed
# as relative percentage * N cores on system. An 8 CPU core system would accept
# values from 0 - 800, a 12 cores system would accept 0 - 1200 etc...
inotify_cpulimit="0"

##
# [ STATISTICAL ANALYSIS ]
# This is a beta feature and as such should be used with caution.
# Currently, this feature can have a substantially negative impact
# on scan performance, especially with large file sets.
##
# The string length test is used to identify threats based on the
# length of the longest uninterrupted string within a file. This is
# useful as obfuscated code is often stored using encoding methods
# that produce very long strings without spaces (e.g: base64)
# [ string length in characters, default = 150000 ]
string_length_scan="0"		# [ 0 = disabled, 1 = enabled ]
string_length="150000"		# [ max string length ]

Kurulum ve ayarlamalar bu kadar, şimdi sunucuda kullanımına bakacak olursak; Sunucu üzerinde tam tarama için;

maldet -a

Sunucuda belirli bir kullanıcıyı taramak için;

maldet -a /home/kullanıcıadi/public_html

Komutlarını kullanabilirsiniz. İyi çalışmalar.