CERT-Polska / karton-config-extractor

Static configuration extractor for the Karton framework

Config-extractor karton service

Extracts static configuration from samples and memory dumps using the malduck engine.

Author: CERT.pl

Maintainers: nazywam, psrok1, msm

Consumes:

{
    "type": "sample",
    "stage": "recognized",
    "kind": "runnable",
    "platform": "win32"
},
{
    "type": "sample",
    "stage": "recognized",
    "kind": "runnable",
    "platform": "win64"
},
{
    "type": "sample",
    "stage": "recognized",
    "kind": "runnable",
    "platform": "linux"
},
{
    "type": "analysis",
},

While sample type is self explanatory, the analysis type might be confusing. The analysis task is an output from one of sandboxes: drakvuf-sandbox, cuckoo, or joesandbox. Analysis is a sample with additional memory dumps attached.

The analysis type task is expected to be in format:

task = Task(
    headers={"type": "analysis"}
    payload={
        "sample": <sample>,
        "dumps.zip": Resource.from_directory("dumps.zip", dumps_path.as_posix()),
        "dumps_metadata": [
            {"filename": <dump1_filename>, "base_address": <dump1_base_address>},
            {"filename": <dump2_filename>, "base_address": <dump2_base_address>},
            {"filename": <dump3_filename>, "base_address": <dump3_base_address>},
            [...]
        ],
    }
)

where dumps_metadata contains information about filename and base address for every memory dump in dumps.zip. The following attributes are:

• filename which is relative path to the dumps.zip contents;
• base_address which hex-encoded base address for dump (leading 0x is supported) You can specify multiple entries for the same file if the same memory dump was found on different base addresses.

The extractor tries to retrieve config from each memory dump and will pick only the best candidate from each malware family.

Produces:

# Dropped dumps related with static configuration
{
    "type": "sample",
    "stage": "analyzed",
    "kind": "dump",
    "platform": "win32",
    "extension": "exe"
    "payload": {
        "sample": <Resource>, # Dump where config was found
        "parent": <Resource>  # Original executable
    }
}

# Static configuration
{
    "type": "config",
    "family": <str>, # Family name
    "payload": {
        "config": <dict>,     # Static configuration
        "sample": <Resource>, # Dump where config was found
        "parent": <Resource>, # Original executable
    }
}

Usage

First of all, make sure you have setup the core system: https://github.com/CERT-Polska/karton

Then install karton-config-extractor from PyPi:

$ pip install karton-config-extractor

$ karton-config-extractor --modules malduck-extractor-modules/