bdasm is a PyCommand written for Immunity Debugger version 1.73. It searches the address space of a process for a certain opcode/instruction and dissasembles backwards and forwards for a specified number of instructions.
You can download it from the following link: https://packetstormsecurity.com/files/download/94340/bdasm.py.txt
Source: https://packetstormsecurity.com/files/94340/Backward-Disassembler-For-ROP-Exploitation.html