Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 371823ac15f3688e…

MALICIOUS

Office (OLE) / .XLS

114.7 KB Created: 2022-01-24 01:40:11 Authoring application: Microsoft Excel
MD5: 8832f18539323a70f2496aee9f454731 SHA-1: b8fc7cf089657e72a2fe80562b12fc5812d56e1d SHA-256: 371823ac15f3688eb7a36b990554a9faa7832b3ba74e641e8576af59b8af4c34
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 an Excel 4.0 spreadsheet containing an Auto_Open macro, a known technique for executing malicious code. ClamAV detection explicitly identifies it as 'Xls.Downloader.Emotet', strongly suggesting the Emotet family. The macro's presence and the ClamAV signature indicate the file's purpose is 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