Linux에서 'Rootkit Hunter'를 사용하여 루트킷, 백도어 및 악용을 검색하는 방법
여러분, linux-console.net의 정기 독자라면 이것이 보안 도구에 대한 세 번째 기사라는 것을 알게 될 것입니다. 이전 두 기사에서는 악성 코드, DOS, 및 DDOS mod_security, mod_evasive 및 LMD(Linux Malware Detect)를 사용한 공격.
다시 한 번 Rkhunter(Rootkit Hunter)라는 새로운 보안 도구를 소개합니다. 이 문서에서는 소스 코드를 사용하여 Linux 시스템에 RKH(RootKit Hunter)를 설치하고 구성하는 방법을 안내합니다.
Rkhunter 란 무엇입니까?
Rkhunter(Rootkit Hunter)는 GPL에 따라 출시된 Linux 시스템용 오픈 소스 Unix/Linux 기반 스캐너 도구로, 백도어, 루트킷 및 시스템에 대한 로컬 악용.
숨겨진 파일, 바이너리에 설정된 잘못된 권한, 커널의 의심스러운 문자열 등을 검사합니다. Rkhunter 및 해당 기능에 대한 자세한 내용을 보려면 http://rkhunter.sourceforge.net/을 방문하세요.
Linux 시스템에 Rootkit Hunter Scanner 설치
1단계: Rkhunter 다운로드
먼저 http://rkhunter.sourceforge.net/으로 이동하여 Rkhunter 도구의 최신 안정 버전을 다운로드하거나 아래 Wget 명령을 사용하여 시스템에 다운로드하세요. .
cd /tmp
wget http://downloads.sourceforge.net/project/rkhunter/rkhunter/1.4.6/rkhunter-1.4.6.tar.gz2단계: Rkhunter 설치
최신 버전을 다운로드한 후 루트 사용자로 다음 명령을 실행하여 설치하세요.
tar -xvf rkhunter-1.4.6.tar.gz
cd rkhunter-1.4.6
./installer.sh --layout default --install샘플 출력
Checking system for:
Rootkit Hunter installer files: found
A web file download command: wget found
Starting installation:
Checking installation directory "/usr/local": it exists and is writable.
Checking installation directories:
Directory /usr/local/share/doc/rkhunter-1.4.2: creating: OK
Directory /usr/local/share/man/man8: exists and is writable.
Directory /etc: exists and is writable.
Directory /usr/local/bin: exists and is writable.
Directory /usr/local/lib64: exists and is writable.
Directory /var/lib: exists and is writable.
Directory /usr/local/lib64/rkhunter/scripts: creating: OK
Directory /var/lib/rkhunter/db: creating: OK
Directory /var/lib/rkhunter/tmp: creating: OK
Directory /var/lib/rkhunter/db/i18n: creating: OK
Directory /var/lib/rkhunter/db/signatures: creating: OK
Installing check_modules.pl: OK
Installing filehashsha.pl: OK
Installing stat.pl: OK
Installing readlink.sh: OK
Installing backdoorports.dat: OK
Installing mirrors.dat: OK
Installing programs_bad.dat: OK
Installing suspscan.dat: OK
Installing rkhunter.8: OK
Installing ACKNOWLEDGMENTS: OK
Installing CHANGELOG: OK
Installing FAQ: OK
Installing LICENSE: OK
Installing README: OK
Installing language support files: OK
Installing ClamAV signatures: OK
Installing rkhunter: OK
Installing rkhunter.conf: OK
Installation complete
3단계: Rkhunter 업데이트
다음 명령을 실행하여 RKH 업데이트 프로그램을 실행하여 데이터베이스 속성을 채웁니다.
/usr/local/bin/rkhunter --update
/usr/local/bin/rkhunter --propupd샘플 출력
[ Rootkit Hunter version 1.4.6 ]
Checking rkhunter data files...
Checking file mirrors.dat [ Updated ]
Checking file programs_bad.dat [ No update ]
Checking file backdoorports.dat [ No update ]
Checking file suspscan.dat [ No update ]
Checking file i18n/cn [ No update ]
Checking file i18n/de [ No update ]
Checking file i18n/en [ No update ]
Checking file i18n/tr [ No update ]
Checking file i18n/tr.utf8 [ No update ]
Checking file i18n/zh [ No update ]
Checking file i18n/zh.utf8 [ No update ]
Checking file i18n/ja [ No update ]
File created: searched for 177 files, found 131, missing hashes 1
4단계: Cronjob 및 이메일 경고 설정
/etc/cron.daily/ 아래에 rkhunter.sh라는 파일을 생성합니다. 이 파일은 매일 파일 시스템을 검사하고 이메일 알림을 보냅니다. 귀하의 이메일 ID로. 원하는 편집기를 사용하여 다음 파일을 만듭니다.
vi /etc/cron.daily/rkhunter.sh여기에 다음 코드 줄을 추가하고 "YourServerNameHere"를 "서버 이름" 및 "[이메일 보호됨]'을 '이메일 ID'로 바꿉니다.
#!/bin/sh
(
/usr/local/bin/rkhunter --versioncheck
/usr/local/bin/rkhunter --update
/usr/local/bin/rkhunter --cronjob --report-warnings-only
) | /bin/mail -s 'rkhunter Daily Run (PutYourServerNameHere)' [email 파일에 대한 실행 권한을 설정합니다.
chmod 755 /etc/cron.daily/rkhunter.sh5단계: 수동 검색 및 사용
전체 파일 시스템을 검사하려면 루트 사용자로 Rkhunter를 실행하세요.
rkhunter --check샘플 출력
[ Rootkit Hunter version 1.4.6 ]
Checking system commands...
Performing 'strings' command checks
Checking 'strings' command [ OK ]
Performing 'shared libraries' checks
Checking for preloading variables [ None found ]
Checking for preloaded libraries [ None found ]
Checking LD_LIBRARY_PATH variable [ Not found ]
Performing file properties checks
Checking for prerequisites [ OK ]
/usr/local/bin/rkhunter [ OK ]
/usr/sbin/adduser [ OK ]
/usr/sbin/chkconfig [ OK ]
/usr/sbin/chroot [ OK ]
/usr/sbin/depmod [ OK ]
/usr/sbin/fsck [ OK ]
/usr/sbin/fuser [ OK ]
/usr/sbin/groupadd [ OK ]
/usr/sbin/groupdel [ OK ]
/usr/sbin/groupmod [ OK ]
/usr/sbin/grpck [ OK ]
/usr/sbin/ifconfig [ OK ]
/usr/sbin/ifdown [ Warning ]
/usr/sbin/ifup [ Warning ]
/usr/sbin/init [ OK ]
/usr/sbin/insmod [ OK ]
/usr/sbin/ip [ OK ]
/usr/sbin/lsmod [ OK ]
/usr/sbin/lsof [ OK ]
/usr/sbin/modinfo [ OK ]
/usr/sbin/modprobe [ OK ]
/usr/sbin/nologin [ OK ]
/usr/sbin/pwck [ OK ]
/usr/sbin/rmmod [ OK ]
/usr/sbin/route [ OK ]
/usr/sbin/rsyslogd [ OK ]
/usr/sbin/runlevel [ OK ]
/usr/sbin/sestatus [ OK ]
/usr/sbin/sshd [ OK ]
/usr/sbin/sulogin [ OK ]
/usr/sbin/sysctl [ OK ]
/usr/sbin/tcpd [ OK ]
/usr/sbin/useradd [ OK ]
/usr/sbin/userdel [ OK ]
/usr/sbin/usermod [ OK ]
....
[Press to continue]
Checking for rootkits...
Performing check of known rootkit files and directories
55808 Trojan - Variant A [ Not found ]
ADM Worm [ Not found ]
AjaKit Rootkit [ Not found ]
Adore Rootkit [ Not found ]
aPa Kit [ Not found ]
.....
[Press to continue]
Performing additional rootkit checks
Suckit Rookit additional checks [ OK ]
Checking for possible rootkit files and directories [ None found ]
Checking for possible rootkit strings [ None found ]
....
[Press to continue]
Checking the network...
Performing checks on the network ports
Checking for backdoor ports [ None found ]
....
Performing system configuration file checks
Checking for an SSH configuration file [ Found ]
Checking if SSH root access is allowed [ Warning ]
Checking if SSH protocol v1 is allowed [ Warning ]
Checking for a running system logging daemon [ Found ]
Checking for a system logging configuration file [ Found ]
Checking if syslog remote logging is allowed [ Not allowed ]
...
System checks summary
=====================
File properties checks...
Files checked: 137
Suspect files: 6
Rootkit checks...
Rootkits checked : 383
Possible rootkits: 0
Applications checks...
Applications checked: 5
Suspect applications: 2
The system checks took: 5 minutes and 38 seconds
All results have been written to the log file: /var/log/rkhunter.log
One or more warnings have been found while checking the system.
Please check the log file (/var/log/rkhunter.log)
위 명령은 Rkhunter의 확인 결과와 함께 /var/log/rkhunter.log 아래에 로그 파일을 생성합니다.
cat /var/log/rkhunter.log
샘플 출력
[11:21:04] Running Rootkit Hunter version 1.4.6 on tecmint
[11:21:04]
[11:21:04] Info: Start date is Mon Dec 21 11:21:04 AM IST 2020
[11:21:04]
[11:21:04] Checking configuration file and command-line options...
[11:21:04] Info: Detected operating system is 'Linux'
[11:21:04] Info: Found O/S name: Fedora release 33 (Thirty Three)
[11:21:04] Info: Command line is /usr/local/bin/rkhunter --check
[11:21:04] Info: Environment shell is /bin/bash; rkhunter is using bash
[11:21:04] Info: Using configuration file '/etc/rkhunter.conf'
[11:21:04] Info: Installation directory is '/usr/local'
[11:21:04] Info: Using language 'en'
[11:21:04] Info: Using '/var/lib/rkhunter/db' as the database directory
[11:21:04] Info: Using '/usr/local/lib64/rkhunter/scripts' as the support script directory
[11:21:04] Info: Using '/usr/local/sbin /usr/local/bin /usr/sbin /usr/bin /bin /sbin /usr/libexec /usr/local/libexec' as the command directories
[11:21:04] Info: Using '/var/lib/rkhunter/tmp' as the temporary directory
[11:21:04] Info: No mail-on-warning address configured
[11:21:04] Info: X will be automatically detected
[11:21:04] Info: Found the 'basename' command: /usr/bin/basename
[11:21:04] Info: Found the 'diff' command: /usr/bin/diff
[11:21:04] Info: Found the 'dirname' command: /usr/bin/dirname
[11:21:04] Info: Found the 'file' command: /usr/bin/file
[11:21:04] Info: Found the 'find' command: /usr/bin/find
[11:21:04] Info: Found the 'ifconfig' command: /usr/sbin/ifconfig
[11:21:04] Info: Found the 'ip' command: /usr/sbin/ip
[11:21:04] Info: Found the 'ipcs' command: /usr/bin/ipcs
[11:21:04] Info: Found the 'ldd' command: /usr/bin/ldd
[11:21:04] Info: Found the 'lsattr' command: /usr/bin/lsattr
...
자세한 내용과 옵션을 보려면 다음 명령을 실행하세요.
rkhunter --help이 기사가 마음에 들었다면 공유하는 것이 감사를 표현하는 올바른 방법입니다.