Emotet — Office (OOXML) / .XLSM malware analysis

Static analysis result for SHA-256 e2028c07e450fd79…

MALICIOUS

Office (OOXML) / .XLSM

50.5 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2022-03-11
MD5: 0ee4abcca15d04604a6cc6f76500e0ab SHA-1: d3b7780d7700e246afa984e30145d02254b78b5a SHA-256: e2028c07e450fd7915ae381326673ee38a33299b0abf7ffd172534e3da7588a6
290 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 malicious Excel 4.0 macro-enabled document (XLSM) utilizes dangerous formula APIs to download and execute a payload. The script explicitly calls regsvr32.exe with a URL pointing to a potential second-stage payload, indicating an Ingress Tool Transfer (T1105) and System Binary Proxy Execution via Regsvr32 (T1218.010). The ClamAV detection as 'Xls.Downloader.Emotet' strongly suggests the Emotet family.

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.Emotet03220-9941298-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet03220-9941298-0
  • 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://actividades.laforetlanguages.com/wp-admin/WQNAwrWi77MV8a05fia/
    • http://aopda.org/wp-content/uploads/KXc3Agu18w/
    • http://advogadogoiania.com.br/wp-includes/VTz0V6D/
    • https://www.agenciaigual.com.br/Novo2017/yTZMu9FxcyHYFUkb/
    • http://consejosdeorlando.com/wp-includes/mMaIlj99Y1C1sYN/
    • http://agenciaml.com.br/wp-content/lMGfW5Wk09k/
    • http://101.53.142.76/ApcCache/FiXQvn/
    • 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
b99514d31bf111baca7178f1c3b7e161c3a1df476cfbefb5ab0d85aee00a0f99
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 4031 bytes
xlm_sheet_01.xml
57ec544c624f64a940b22b418ecc97356699a87d8f5405ae8ca128da00e7393a
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 1277 bytes
xlm_sheet_02.xml
1a2bbba2a276f955ce94cee47252cbd0a00ecbdfcf526f95f8e33343bc612848
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.xml 1152 bytes