Emotet — Office (OOXML) / .XLSM malware analysis

Static analysis result for SHA-256 08785f87fe88f697…

MALICIOUS

Office (OOXML) / .XLSM

73.0 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2022-03-15
MD5: fed448dd2ba85016c1a5a8084443508c SHA-1: b89072e102cc5b8ec14908d370b158b6052dd135 SHA-256: 08785f87fe88f697b9922a1f1f310359e123aa1a8d7cd463fe02ed74b8908918
290 Risk Score

Malware Insights

Emotet · confidence 95%

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

The file contains critical Excel 4.0 macros, including an Auto_Open defined name and dangerous formula APIs like FORMULA, which are used to download payloads. The macros construct URLs and then use `regsvr32.exe` to execute a DLL from a remote location, consistent with Emotet's known behavior. The presence of multiple suspicious URLs further supports this assessment.

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.Emotet03220-9941786-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet03220-9941786-0
  • 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 6 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://andjello.net/wp-includes/O74XNLzsodp/
    • http://anneferrier.com/logs/Ia7oz193SZbb5N/
    • http://allamapianoawards.com/quisint/RanfoIJhasZ0R33o/
    • https://www.anagramme.net/admin_files/rOzDUUhjSMh/
    • http://andrewpharma.com/wp-includes/d8yxEkWRUU/
    • http://anaforainc.com/media/tUKKnlCd0QJDxWO/
    • http://amdrolls.com/Template/goRpY/
    • 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
561bd2ad03d5ff349d3a0a4fbda71b956dd8d97a0dbce4e25549bf8a7721c5df
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 4049 bytes
xlm_sheet_01.xml
4f892349a6f0ce9450df5d764f02eea0a737d43225bc39e0b3e39eaafe266901
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 1276 bytes
xlm_sheet_02.xml
f8dcec9dac216a8c4fc7140768d73598afe199c381abfb2f58ad13ed8f5733f6
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.xml 1152 bytes