GREM Bypassing Packers and Obfuscation 2

Question 1

Which OllyDbg plugin is specifically designed to automatically unpack many common packers by monitoring the OEP transfer?

Accepted Answer

OllyDbg Unpacker (OUP)

Answer

StrongOD

Answer

OllyDump

Answer

ImpREC

Question 2

When a packer uses a 'TLS callback' to execute code before the debugger's initial breakpoint, the analyst should:

Accepted Answer

Set a breakpoint on the TLS callback address listed in PE headers before execution begins

Answer

Disable all hardware breakpoints before loading the sample

Answer

Attach the debugger after the process is already running

Answer

Use only software breakpoints on the entry point

Question 3

The 'tail jump' technique in manual unpacking refers to:

Accepted Answer

A JMP instruction at the end of the stub that transfers control to the original entry point

Answer

Encoding the last section of the PE with XOR

Answer

A call to VirtualAlloc at the very end of execution

Answer

Appending decoy code after the real OEP

Question 4

Which Windows API function is most commonly used by packers to allocate a new executable memory region for decompressed code?

Accepted Answer

VirtualAlloc

Answer

HeapAlloc

Answer

GlobalAlloc

Answer

LocalAlloc

Question 5

An analyst observes that a packed sample checks the BeingDebugged flag in the PEB. The most direct way to bypass this check is:

Accepted Answer

Manually patch the BeingDebugged byte to 0 in memory while debugging

Answer

Use kernel-mode debugging instead

Answer

Disable the TLS callbacks

Answer

Set hardware breakpoints instead of software breakpoints

Question 6

When using x64dbg to find the OEP of a packed 64-bit binary, which feature helps by logging all calls to GetProcAddress?

Accepted Answer

Conditional breakpoint on GetProcAddress that logs the return value

Answer

Run trace with logging enabled

Answer

Hardware execution breakpoint on kernel32.dll

Answer

Scripting engine to dump imports automatically

Question 7

A sample uses 'stolen bytes' obfuscation, where the first few bytes of the OEP are moved into the unpacking stub. This complicates analysis because:

Accepted Answer

Dumping the unpacked image produces a broken entry point missing its original instructions

Answer

The IAT cannot be rebuilt by any tool

Answer

Hardware breakpoints cannot be placed on the OEP

Answer

The PE header is completely destroyed