Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 c1f886a6500102aa…

MALICIOUS

Office (OLE) / .XLS

115.3 KB Created: 2022-01-24 01:40:11 Authoring application: Microsoft Excel
MD5: 1cc13d88f4fabeaed76ecf4be4896bad SHA-1: abe1f621de1f645c668b0fdd4fd4076968a11336 SHA-256: c1f886a6500102aaa3139fa37f145a3cf684c795e4425cc81a932409dbd6b5fe
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1566.001 Spearphishing Attachment

The file is detected as malicious by ClamAV and exhibits critical heuristic firings for Excel 4.0 macros, including an Auto_Open function that uses dangerous APIs like RUN. This indicates the macro is designed to execute arbitrary commands. The presence of an Auto_Open macro suggests a delivery mechanism intended to run code automatically upon opening the spreadsheet, likely to download and execute a second-stage payload.

Heuristics 4

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • ClamAV: Xls.Downloader.Emotet-bd646319c2d29cd6-9951195-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-bd646319c2d29cd6-9951195-0
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
86637063ac2c97bbefdbc9033f21cd30e9484ed274aba63ad50d62dfa1de93cd
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 4341 bytes