Emotet — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 0f550429f77ebcb1…

MALICIOUS

Office (OLE) / .XLSX

142.2 KB Created: 2022-01-26 02:21:30 Authoring application: Microsoft Excel
MD5: 06005f8065da73eaaf842522691d0667 SHA-1: eae99998acfdb5c6f140c1f851b1a171181a79b8 SHA-256: 0f550429f77ebcb1e5fce719b9bbfce2f5ea0e0787f2e013635335b3d584d51a
200 Risk Score

Malware Insights

Emotet · confidence 95%

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

The file contains Excel 4.0 macros, specifically an Auto_Open entry, which is a known technique for executing malicious code. ClamAV identified the file as 'Xls.Downloader.Emotet', strongly suggesting the Emotet family. The macro's presence and the ClamAV signature indicate the file's primary purpose is to download and execute a secondary 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
46284ea41c691066b9fe85a87bc7e9bfc77336182ea3b4ed700574b0c8cd3189		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 3141 bytes

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