Emotet — Office (OOXML) / .XLSM malware analysis

Static analysis result for SHA-256 617f570108b516a7…

MALICIOUS

Office (OOXML) / .XLSM

44.7 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2022-03-11
MD5: 7fbf2dfd2cb5e0195c667075f7c4a5fe SHA-1: 681bab5910bf577b73b9266606538792c445de0e SHA-256: 617f570108b516a74b57c7452feac3049d24c70a36bc0084a7c25a98d15d5822
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 that utilize dangerous formula APIs like FORMULA to download and execute payloads. The macros construct commands to use regsvr32.exe to download a file from one of the embedded URLs, such as 'http://www.agretto.com/Template/ziasuz5w8pS08Gm2/', and save it as '..\wn.ocx'. This behavior is characteristic of Emotet downloaders.

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.Emotet03221-9941289-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet03221-9941289-0
  • 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 http://www.agretto.com/Template/ziasuz5w8pS08Gm2/
    • https://lifebotl.com/Response/WllkQWM/
    • http://185.187.70.35/wordpress_bo/srvoaI2MBFc/
    • http://103.85.95.5/v1/uploads/87DtpAEZULSccOn/
    • http://www.agnesleung.com/raw.backup/j4ry/
    • https://livejagat.com/h/SjpRvD/
    • http://188.166.245.112/sipadu/eFi8UiJETZiK1FB/
    • 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
aa639861ddc5b5835fc6dc55f810a8cdd345d5a0f25a9228a1e87fb64257685f
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 4348 bytes
xlm_sheet_01.xml
ff04c6af5f59c8590aa4a7b71a1b2742e5c5b487ad6a63ca1d90a970ae623c5f
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 1277 bytes
xlm_sheet_02.xml
33ff727dfe6d455b4500b1331dbc121c2312bb4ec71c24948d23118c341dc852
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.xml 1213 bytes