Video: 2-Minutes QakBot Excel Malware Analysis

The script extends the Silicon Excel Emulator by implementing the “NOW” and “FORMULA.FILL” functions:

from Pro.SiliconSpreadsheet import *
from Pro.UI import proContext

class EmulatorHelper(SiliconExcelEmulatorHelper):

    def __init__(self):
        super(EmulatorHelper, self).__init__()
    def evaluateFunction(self, emu, ctx, opts, depth, e):
        function_name = e.toString()
        if function_name == "FORMULA.FILL":
            if emu.expectedArguments(e, 2, 2):
                ve = emu.argToValue(ctx, opts, depth, e, 0)
                v = emu.valueToSpreadsheetValue(ve)
                idxstr = emu.argToValue(ctx, 0, depth, e, 1).toString()
                idx = SiliconSpreadsheetUtil.cellIndex(idxstr)
                print("FORMULA.FILL:", idxstr, "=", emu.valueToString(ve))
                # add the cell to the sheet
                ws = emu.getWorkspace()
                sheet_idx = ws.sheetIndexFromName(idx.sheet if idx.sheet else ctx.idx.sheet)
                sheet = ws.getSheet(sheet_idx)
                sheet.addCell(idx.column, idx.row, v.type, v.value)
                return SiliconExcelEmulatorValue(SiliconSpreadsheetValueType_Null, 0)
        elif function_name == "NOW":
            return SiliconExcelEmulatorValue(SiliconSpreadsheetValueType_Number, "44249.708602")
        return SiliconExcelEmulatorValue()

v = proContext().findView("Analysis [qakbot_xls_0]")
if v.isValid():
    view = SiliconSpreadsheetWorkspaceView(v)
    helper = EmulatorHelper()
    emu = view.getExcelEmulator()
    print("error: couldn't find view")

Leave a Reply

Your email address will not be published. Required fields are marked *