Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 8c3cfdd7e1e16212…

MALICIOUS

Office (OLE) / .XLS

255.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-11-08
MD5: 18252d898a785e916760be3e63c29a78 SHA-1: 769301632d80a6c5996e7f9514786e79d044db17 SHA-256: 8c3cfdd7e1e162129eedf2c3d9f6f63c133622bfe5d04bccbd823486a85b69ed
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File

The file contains Excel 4.0 macros, specifically an Auto_Open macro, which is a known technique for executing malicious code. ClamAV detection confirms this is an Emotet downloader variant. The macro's use of dangerous functions like RUN indicates it is 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-b649c93692b4c9d9-9976616-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-b649c93692b4c9d9-9976616-0
  • 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
547e4a6ee70f83816986c249acc1b8d54387375bab701abb3a1db6d58c8d2182
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8305 bytes