Emotet — Office (OOXML) / .XLSM malware analysis

Static analysis result for SHA-256 a37e68049dd1c51d…

MALICIOUS

Office (OOXML) / .XLSM

43.3 KB Authoring application: 14.0300 First seen: 2022-03-06
MD5: c8ea6b63eaa31c9face85e0d288e28e4 SHA-1: 9cdf8b4fcd8acaafe2e877c8559f3cf9a3e26799 SHA-256: a37e68049dd1c51d49c24f1eea9c59403b337a30fb734b1cef73babd423ccd1f
230 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 that leverage dangerous API functions like FORMULA to construct and execute commands. The macros are designed to download and execute a second-stage payload using regsvr32.exe with URLs pointing to malicious sites. The ClamAV detection and heuristic firings strongly indicate this is an Emotet downloader.

Heuristics 6

  • Excel 4.0 macro sheet (1 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.
  • 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.Emotet03220-9940726-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet03220-9940726-0
  • 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 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://nataliapereira.com/wp-admin/pE8xYY3x6p/
    • http://annewelshsalon.com/wp-admin/2c9l2o1/cWWAzTVQ/
    • http://hellocloudgurusgerald.com/wp-content/iXYx/
    • https://ramijabali.com/licenses/0/
    • https://africa-roadworks.com/lilo-bard/vk3GSY7/
    • http://schemas.openxmlformats.org/spreadsheetml/2006/main
    • http://schemas.openxmlformats.org/officeDocument/2006/relationships
    • http://schemas.openxmlformats.org/drawingml/2006/spreadsheetDrawing
    • http://schemas.microsoft.com/office/spreadsheetml/2009/9/main
    • http://schemas.openxmlformats.org/markup-compatibility/2006
    • http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac
    • http://schemas.microsoft.com/office/excel/2006/main
    • 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml
4c2ab2a64e86303bed33459056f59d3a9bad8bdcab0da38642ea0eae51d4cf13
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 3782 bytes