Inroduction

Amber is a position-independent(reflective) PE loader that enables in-memory execution of native PE files(EXE, DLL, SYS...). It enables stealthy in-memory payload deployment that can be used to bypass anti-virus, firewall, IDS, IPS products, and application white-listing mitigations. Reflective payloads generated by Amber can either be staged from a remote server or executed directly in memory much like a generic shellcode. By default, every generated payload is encoded using the new generation SGN encoder. Amber uses CRC32_API and IAT_API for inconspicuously resolving the Windows API function addresses. After the PE file is loaded and executed in memory, the reflective payload is erased for evading memory scanners.

Installation

Pre-compiled binaries can be found under releases.

Building From Source

The only dependency for building the source is the keystone engine, follow these instructions for installing the library. Once libkeystone is installed on the system, simply just go get it ツ

go install github.com/EgeBalci/amber@latest

Docker Install

docker pull egee/amber
docker run -it egee/amber

Usage

The following table lists switches supported by the amber.

Switch	Type	Description
-f,--file	string	Input PE file.
-o,--out	string	Output binary payload file name.
-e	int	Number of times to encode the generated reflective payload
--iat	bool	Use IAT API resolver block instead of CRC API resolver block
-l	int	Maximum number of bytes for obfuscation (default 5)
--sys	bool	Perform raw syscalls. (only x64)
--scrape	bool	Scrape magic byte and DOS stub from PE.

Example Usage

• Generate reflective payload.

amber -f test.exe

• Generate reflective payload with IAT API resolver and encode the final payload 10 times.

amber -e 10 --iat -f test.exe

Docker Usage

docker run -it -v /tmp/:/tmp/ amber -f /tmp/file.exe

Demo

• NOPcon 2018 DEMO
• Pentest.blog - Deploying Reflective PE Files With Metasploit
• Pentest.blog - Deploying Reflective Ransomware POC