Code Playground

General repository for experimenting with different coding languages

Assembly

ww.asm - "Hello World" example which prints "wakeward" rs.asm - reverse shell in assembly Thx Xre0uS

Build and Execution

ww.asm

nasm -f elf32 ww.asm -o ww.o
ld -m elf_i386 ww.o -o ww

./ww

rs.asm

Setup nc listener

nc -nlvp 4444

Build and Execute

nasm -f elf64 rs.asm -o rs.o
ld rs.o -o rs

./rs

Notes from code reviewing

From rs.asm

• CDQ - Covert Doubleword to Quadword is an instruction that extends the sign bit of EAX into the EDX register.
• syscall - is default way of entering kernel mode on x86-64. This instruction is not available in 32 bit modes of operation on Intel processors.
• XCHG - Exchanges (swaps) the value of 2 registers
• JNS - Jump if not sign
• SIL - General purpose register (64-bit, the least significant bit 8 bits is assessible)

Ref

Go

Testing

go run main.go

Build for Linux (current environment)

go build -o rs main.go

C

Build

gcc rs.c -o rs