Emotet — Office (OOXML) / .XLSM malware analysis

Static analysis result for SHA-256 0b564ff5c20ebc43…

MALICIOUS

Office (OOXML) / .XLSM

209.3 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2022-02-23
MD5: 663dad019e7719c70209ee5caff50db3 SHA-1: a736029306d4d8ff11b4f14d4b32f2d442431fdd SHA-256: 0b564ff5c20ebc43cf8606b6428cb4d73d9903969ddd4073a1647dfa28db5d05
290 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1218.010 System Binary Proxy Execution: Regsvr32 T1105 Ingress Tool Transfer

The file is an XLSM document containing Excel 4.0 macros, which is a strong indicator of malicious intent, specifically associated with the Emotet family. The macros utilize dangerous API calls like FORMULA to construct and execute commands. The embedded URLs and the use of regsvr32.exe indicate that the primary function is to download and execute a second-stage payload from a remote server.

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.EmotetRed022217-9940031-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.EmotetRed022217-9940031-0
  • 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 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 https://www.swaong.com/assets/VV4/
    • http://vulkanvegasbonus.jeunete.com/wp-content/7uAnLq8I/
    • http://old.liceum9.ru/images/images/NKeRl/
    • http://arttop100.cn/wp-admin/DvyJPADMPW/
    • http://peterjacksoncars.com.au/wp-content/sJ/
    • 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
6dd9356952cdd6b95caf156e3e1c1471d7e098b9395e326c2a5a80643c35f018
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 3546 bytes
xlm_sheet_01.xml
966e861f35410708893ffb1f97241504111fc93333012aa9c7613d379c3c60bb
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 1204 bytes
xlm_sheet_02.xml
60579741b1b65a4181fd818a651bece32da461189f50a30098e233a7c5fed525
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.xml 1227 bytes