Feature Request cx_freeze main stub detection

[Siradankullanici]

import "pe"
import "elf"

rule Detect_cx_Freeze_MainStub
{
    meta:
        description = "Detect cx_Freeze main stub on PE or ELF"
        author = "Emirhan Ucan"
        license = "GPLv2"
        reference = "https://github.com/marcelotduarte/cx_Freeze/blob/7ae7fc3bf7422dc24ed5c5f1c08041b5646ad286/source/legacy/Win32GUI.c#L17"
        sha256 = "a715be2a6784804be97884a45f847011d8f1c7c546607e5fef1bf1accaad8dec"
        date = "2025-06-04"

    strings:
        $s1 = "cx_Freeze: Python error in main script" ascii
        $s2 = "cx_Freeze Fatal Error" ascii

    condition:
        pe.is_pe and all of ($s1, $s2) or
        elf.type != 0 and all of ($s1, $s2)
}

I created YARA rule for that detect cx_freeze main script

[hypn0chka]

@Siradankullanici Could you share two or three samples of such files? Because the detection by text strings will work extremely slowly if the file is large enough. With samples I will be able to make a faster and better detection of cx_Freeze.

[Siradankullanici]

Here is the files which works on latest cx_freeze but not in older cx_freeze (antivirus.exe older cx_freeze but newer one is main.exe)

examples.zip

[DosX-dev]

Thank you, we'll definitely consider your work

[Siradankullanici]

Ok I find the reason why it only detects GUI version of main stub because it's for GUI not console.

[Siradankullanici]

// cx_Freeze main stub detector for 5.x+
// Emirhan Uçan <semaemirhan555@gmail.com>
init("packer", "cx_Freeze(5.x+)", "Python", "");

function detect() {
    if (typeof PE === 'undefined') return false;

    var pythonDlls = [
        "python27.dll", "python35.dll", "python36.dll", "python37.dll",
        "python38.dll", "python39.dll", "python310.dll", "python311.dll",
        "python312.dll", "python313.dll"
    ];

    var foundDll = null;
    for (var i = 0; i < pythonDlls.length; i++) {
        if (PE.isLibraryPresent(pythonDlls[i])) {
            foundDll = pythonDlls[i];
            break;
        }
    }
    if (!foundDll) return false;

    var apiFns = [
        "PyObject_GetAttrString", "PySys_SetArgvEx", "PyObject_CallObject",
        "PyRun_SimpleString", "Py_Initialize", "Py_Finalize"
    ];
    var hitCount = 0;
    for (var j = 0; j < apiFns.length; j++) {
        if (PE.isLibraryFunctionPresent(foundDll, apiFns[j])) hitCount++;
    }
    if (hitCount < 3) return false;

    if (!checkCxFreezeSignatures()) return false;

    var pyVer = foundDll.replace("python", "").replace(".dll", "");
    if (pyVer.length > 2) pyVer = pyVer.charAt(0) + "." + pyVer.substring(1);

    bDetected = true;
    sVersion = pyVer;
    return result();
}

function checkCxFreezeSignatures() {
    var sigs = [
        "cx_Freeze: Python error in main script",
        "Unable to calculate directory of executable!",
        "Out of memory creating sys.path!",
        "cx_Freeze",
        "library.zip",
        "_cx_freeze",
        "Python is not installed as a framework",
        "Error initializing Python",
        "sys.path",
        "__loader__",
        "frozen"
    ];

    var size = PE.getSize();
    for (var i = 0; i < sigs.length; i++) {
        if (PE.findString(0, size, sigs[i]) !== -1) return true;
    }

    var secs = PE.getNumberOfSections();
    for (var s = 0; s < secs; s++) {
        var off = PE.getSectionFileOffset(s), sz = PE.getSectionFileSize(s);
        if (off >= 0 && sz > 0 && (PE.findString(off, sz, "library.zip") !== -1 || PE.findString(off, sz, "python") !== -1)) return true;
    }

    if (PE.isResourcesPresent && PE.isResourcesPresent()) {
        var resCount = PE.getNumberOfResources();
        for (var r = 0; r < resCount; r++) {
            var name = (PE.getResourceNameByNumber(r) || "").toLowerCase();
            if (name.indexOf("python") !== -1 || name.indexOf("library") !== -1) return true;
        }
    }

    return false;
}

that's probably how should he looks like there few major flaws in the code and standarts but mostly works

[DosX-dev]

Need more samples

[BJNFNE]

Reference if required for Cx_Freeze: https://github.com/marcelotduarte/cx_Freeze/