Dridex — Office (OOXML) / .XLSM malware analysis

Static analysis result for SHA-256 71d7cbf6e61b68b4…

MALICIOUS

Office (OOXML) / .XLSM

210.4 KB Created: 2021-08-16 09:36:27 UTC Authoring application: Microsoft Excel 12.0000
MD5: 71c8947515e798b1f0dd95a5c4880f0b SHA-1: 1fc598b3bc589b260ab039e794a97cb598b1e196 SHA-256: 71d7cbf6e61b68b4812b820b09a720f070f8d909a4240e4bdf5d4a45a3e4c955
250 Risk Score

Malware Insights

Dridex · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

This XLSM file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical indicator of malicious intent. The macros utilize dangerous functions like EXEC, FOPEN, and HALT to download and execute a script file located at 'C:\ProgramData\eFXxdPLBTBqPhN.sct'. The ClamAV detection further confirms its malicious nature, identifying it as a Dridex downloader.

Heuristics 6

  • Excel 4.0 macro sheet (1 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: EXEC, HALT, FOPEN, FWRITE, FCLOSE 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.DridexCyan08210-9887648-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.DridexCyan08210-9887648-0
  • Hidden worksheet (hidden) low OOXML_HIDDEN_SHEET
    Excel workbook contains 1 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml
3833d9197fecfce9556a7ea4327cd224379c9f6d1fd58fdd63dc24c8172ec157		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 124252 bytes

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