Emotet — Office (OOXML) / .XLSM malware analysis

Static analysis result for SHA-256 b559ddbedfcba914…

MALICIOUS

Office (OOXML) / .XLSM

74.1 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2022-03-15
MD5: fe07da737ee1762d78ab5de51e23d34c SHA-1: e2116abfab3d82942c0c44add761e4091f9e4cb5 SHA-256: b559ddbedfcba914692c456b49ee491fdbc889c8fc8cb0860d79922f5fc522a7
250 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

The file is an XLSM document containing Excel 4.0 macros, detected as malicious by ClamAV as 'Xls.Downloader.Emotet03220-9941786-0'. The macros utilize dangerous XLM functions like FORMULA to construct and execute commands. Specifically, it reconstructs URLs such as 'https://thesparklezbox.com/wp-admin/kFkWN/' and 'http://www.asyadegirmen.com/Template/nEMRY55nQgF/' to download and execute a second-stage payload, likely via 'regsvr32.exe' to load 'rds.ocx'. The presence of multiple obfuscated URLs and the use of XLM's direct Win32 API calls strongly indicate a downloader functionality typical of the Emotet family.

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.Emotet03220-9941786-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet03220-9941786-0
  • 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://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
d89b7d38fd8a9e6e956d206d38aaf287302fa490f0a6258530e7eb1289212864		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 3854 bytes
xlm_sheet_01.xml
66bfcd6f779a43381c9703ce8fb35f6a1e698ff56c3952fb486a051b7507578c		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 1275 bytes
xlm_sheet_02.xml
c4c4b38e98fc03e63dbcaf635f5d396461ebdc6c1bd91f6bea98202893777435		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.xml 1213 bytes

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