Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 bb2d474378b6caba…

MALICIOUS

Office (OLE) / .XLS

115.4 KB Created: 2022-01-24 01:40:11 Authoring application: Microsoft Excel
MD5: cd1f07245ba9aa100b6c305f2ab23c8c SHA-1: 1f863d6180fb492b68ae97fbc372ca1655c451af SHA-256: bb2d474378b6caba1fa59b7b1bd530d48833697ae94f9847d2d35362def49e9a
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1059.001 Command and Scripting Interpreter: PowerShell T1566.001 Phishing: Spearphishing Attachment

The sample contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical indicator of malicious intent. The ClamAV detection explicitly names this as 'Xls.Downloader.Emotet-bd646319c2d29cd6-9951195-0', strongly suggesting the Emotet family and a downloader function. The macro's use of dangerous formula APIs like RUN further supports the execution of a 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