Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 ea4f03438e0a0c7f…

MALICIOUS

Office (OLE) / .XLS

114.6 KB Created: 2022-01-24 20:48:09 Authoring application: Microsoft Excel
MD5: 5afa6cfd8062d84457d259ae75fe6840 SHA-1: 8c2e8d83c27dc821fa945fe9444b6cb376b2487f SHA-256: ea4f03438e0a0c7fe70db9091914c3473cb8895de5c584d9f03dcd62a6bdec93
200 Risk Score

Malware Insights

Emotet · confidence 95%

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

The sample is an Excel 4.0 macro-enabled spreadsheet. Heuristics indicate the presence of an Auto_Open macro that uses dangerous functions, specifically the RUN function, which is commonly used to download and execute secondary payloads. ClamAV detection confirms this as Emotet, a known downloader family. The document body content is generic and does not provide specific lures.

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
5a0137a4ff8036cfa03ad914b464e95f104474d870faad94ec8edd89262cb0e9
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 5174 bytes