View8
is a static analysis tool designed to decompile serialized V8 bytecode objects (JSC files) into high-level readable code. To parse and disassemble these serialized objects, View8 utilizes a patched compiled V8 binary. As a result, View8 produces a textual output similar to JavaScript.
- Python 3.x
- Disassembler binary. Available versions:
- V8 Version
9.4.146.24
(Used in Node V16.x) - V8 Version
10.2.154.26
(Used in Node V18.x) - V8 Version
11.3.244.8
(Used in Node V20.x)
For compiled versions, visit the releases page.
input_file
: The input file name.output_file
: The output file name.--path
,-p
: Path to disassembler binary (optional).--disassembled
,-d
: Indicate if the input file is already disassembled (optional).--export_format
,-e
: Specify the export format(s). Options arev8_opcode
,translated
, anddecompiled
. Multiple options can be combined (optional, default:decompiled
).
To decompile a V8 bytecode file and export the decompiled code:
python view8.py input_file output_file
By default, view8
detects the V8 bytecode version of the input file (using VersionDetector.exe
) and automatically searches for a compatible disassembler binary in the Bin
folder. This can be changed by specifing a different disassembler binary, use the --path
(or -p
) option:
python view8.py input_file output_file --path /path/to/disassembler
To skip the disassembling process and provide an already disassembled file as the input, use the --disassembled
(or -d
) flag:
python view8.py input_file output_file --disassembled
Specify the export format(s) using the --export_format
(or -e
) option. You can combine multiple formats:
v8_opcode
translated
decompiled
For example, to export both V8 opcodes and decompiled code side by side:
python view8.py input_file output_file -e v8_opcode decompiled
By default, the format used is decompiled
.
The V8 bytecode version is stored as a hash at the beginning of the file. Below are the options available for VersionDetector.exe
:
-h
: Retrieves a version and returns its hash.-d
: Retrieves a hash (little-endian) and returns its corresponding version using brute force.-f
: Retrieves a file and returns its version.