Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 2e57fb4cc6836cc7…

MALICIOUS

Office (OLE) / .XLS

60.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-06-11
MD5: 4a73efa35417f69d385356bf4ec6b4e4 SHA-1: edb40a893d6ef101232e8812b0c6c0b0ac11aa19 SHA-256: 2e57fb4cc6836cc78ce9c3e0574f08e80e70c5f61b5db85db769d09dba8a0738
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059.001 PowerShell

The sample is an Excel file containing Excel 4.0 macros, specifically an Auto_Open function. This function is designed to execute dangerous API calls, including RUN, which is used to download and execute a second-stage payload. The macro concatenates strings to form URLs, which are then used to fetch the payload. The ClamAV detection name 'Xls.Downloader.Emotet' strongly suggests the Emotet family.

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-ea85817e7e81383e-9951566-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-ea85817e7e81383e-9951566-0
  • 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
cb8f4a1558cb8279c025e418dde008a3fbc444dc0179db1eaa7e9bffce8fea77		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8264 bytes

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