Emotet — Office (OOXML) / .XLSM malware analysis

Static analysis result for SHA-256 325b21b017f7a8c0…

MALICIOUS

Office (OOXML) / .XLSM

40.8 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2022-03-03
MD5: 499b28468bb07d2944ce90879df9748d SHA-1: b5a377c83e92791aafbfe3dda904d68327268338 SHA-256: 325b21b017f7a8c01ccd9cce9e361214b741abe624f06a29f18868b64ed2f815
290 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1218.010 System Binary Proxy Execution: Regsvr32 T1059.005 Command and Scripting Interpreter: Visual Basic T1105 Ingress Tool Transfer

This XLSM file contains Excel 4.0 macros, a known technique for delivering malware. The macros utilize dangerous formula APIs to download and execute a payload using regsvr32.exe. Specifically, the script attempts to download from multiple URLs, including 'http://www.illumeyourimage.com/wp-content/ee9oVF/', and execute it via 'regsvr32.exe /s SysWow64\'. This behavior is consistent with Emotet's downloader functionality.

Heuristics 7

  • Excel 4.0 macro sheet (3 sheet(s)) critical 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 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.
  • ClamAV: Xls.Downloader.Emotet03220-9940731-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet03220-9940731-0
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • Hidden worksheet (hidden) low OOXML_HIDDEN_SHEET
    Excel workbook contains 5 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://www.illumeyourimage.com/wp-content/ee9oVF/
    • https://aircod.com/wp-content/llC0GLSJ/
    • http://massageinnaperville.com/bxs6nk/je1dMHkChYMomdLN/
    • https://sh-alomar.com/buckup/zd803MzrnGATD/
    • http://new.rashed-uzzaman.com/wp-content/6PFTIHR/
    • https://mesinrad.com/google.com/xM15Q/
    • http://www.illumeyourimage.com/w
    • http://schemas.openxmlformats.org/spreadsheetml/2006/main
    • http://schemas.microsoft.com/office/excel/2006/main
    • http://schemas.openxmlformats.org/officeDocument/2006/relationships
    • http://schemas.openxmlformats.org/markup-compatibility/2006
    • http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac
    • http://schemas.microsoft.com/office/spreadsheetml/2014/revision
    • http://schemas.microsoft.com/office/spreadsheetml/2015/revision2
    • http://schemas.microsoft.com/office/spreadsheetml/2016/revision3
    • http://schemas.microsoft.com/office/spreadsheetml/2016/revision6

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml
c2beed76b90707ab99d3556b095847fbe67565665bab2978d4d40d1b769c68e7
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 4017 bytes
xlm_sheet_01.xml
3f1e04bcb932a0d7a0ca09ad6e05d398d7a144c4cda86314010c0ec3e9f94573
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 1278 bytes
xlm_sheet_02.xml
3877aa64e871d2d6fcc766f5b3af64ba0d301f656023d2e6e43652b8210d827c
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.xml 1152 bytes