Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 8acab439fa076e32…

MALICIOUS

Office (OLE) / .XLS

88.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-06-29
MD5: af84a02560274b5308aaa6e5e7dff007 SHA-1: e94dbd166c2ac5f28eab2aecb8a2bbf8239d7af2 SHA-256: 8acab439fa076e32344c4782b9b9037bad8095ce490d3f0f9941177d39c4f1dc
200 Risk Score

Malware Insights

Emotet · confidence 95%

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

The sample is an Excel 4.0 macro-enabled spreadsheet detected by ClamAV as Emotet. The presence of an Auto_Open defined name and the use of dangerous formula APIs like RUN indicate that the macro is designed to execute arbitrary code. This functionality is consistent with Emotet's typical behavior of downloading and executing further malicious payloads.

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-ea81817e7f807ab1-9952142-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-ea81817e7f807ab1-9952142-0
  • 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
5c93687b9d25c0404f878b14fa56e3ca6627083515b2574c08fc5d11ce9b18ba
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8037 bytes