Emotet — Office (OOXML) / .XLSX malware analysis

Static analysis result for SHA-256 2b208c1b8471faeb…

MALICIOUS

Office (OOXML) / .XLSX

144.7 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300
MD5: c4e3d52ee418fa172636d418292bd5d0 SHA-1: cc2647b9e74e411fa41a60a267ca566a74e719f6 SHA-256: 2b208c1b8471faebcf4ecaab6100f8a40557a1b458565bdbcb68cd47920db678
250 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious File: Malicious File T1059.001 Command and Scripting Interpreter: PowerShell T1105 Ingress Tool Transfer

This Excel file contains Excel 4.0 macros, identified by the OOXML_XLM_MACROSHEET and OOXML_XLM_DANGEROUS_FN heuristics. The macros utilize dangerous XLM formula APIs like FORMULA to call Win32 functions, enabling the download and execution of payloads. The reconstructed URLs indicate the file attempts to download a second-stage payload, likely a component of the Emotet banking trojan, as suggested by the ClamAV detection. The script also attempts to use rundll32.exe to execute a downloaded component from the reconstructed URL.

Heuristics 6

  • Excel 4.0 macro sheet (7 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.EmotetRed022215-9938912-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.EmotetRed022215-9938912-0
  • Hidden worksheet (hidden) low OOXML_HIDDEN_SHEET
    Excel workbook contains 9 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 7

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml
845190ff95687dd3bed60f8155a4703d187c9ac3d57c95b5f1e5fbccfcda8bf1		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 3818 bytes
xlm_sheet_01.xml
eb8dc692c1dd2153c89791e81ba8dde6872cd513333852aece5cf5246e9e9be7		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 1339 bytes
xlm_sheet_02.xml
a2c24226987a123df54bf20bea623cddda5aa0848671b3a68fae646b034b0c13		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.xml 1334 bytes
xlm_sheet_03.xml
1afc49d1079b956e7cd6c79b3050d7c6146176d5f88b0641a059978149dc558f		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet3.xml 1337 bytes
xlm_sheet_04.xml
f2beecaf3836e6877dc1d8dcccc0ec6a61ee971bb99fad7ea199d9c4485833ad		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet4.xml 1341 bytes
xlm_sheet_05.xml
33833c2bb127cd3da704c0fa39beca9ede4ef247ba80706d40a7c8cb5fdddbee		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet5.xml 1256 bytes
xlm_sheet_06.xml
9600e9bf835b635afc1c3dbd6b85e16bd1c645dbab403a3c6d8610cff36b8262		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet6.xml 1177 bytes

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