Emotet — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 61137b7d93e2251c…

MALICIOUS

Office (OLE) / .XLSX

114.3 KB Created: 2022-01-24 14:50:55 Authoring application: Microsoft Excel
MD5: fb04d56c7dab3f749e60426e9c19d32a SHA-1: b913c879bf509cbe9e9daf6d882918119f7ae3ad SHA-256: 61137b7d93e2251c2df63f711b5a3b2f97b86e4e8225481b322f2f06b726e8a8
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 function, which is a known technique for executing malicious code. ClamAV identifies the file as 'Xls.Downloader.Emotet-bd646319c2d29cd6-9951195-0', strongly suggesting it's an Emotet downloader variant. The macro's use of dangerous formula APIs like RUN indicates it's designed 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
f65423032a2492710482664c048191ebe835ee4ace2752f1b0fa6e40d416cdf9		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 4885 bytes

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