Emotet Office (OLE) / .XLSX malware analysis — malicious · 8524d24ea83c0c48

MALICIOUS

Office (OLE) / .XLSX

141.9 KB Created: 2022-01-18 14:11:14 Authoring application: Microsoft Excel

MD5: 771d25cc3ac5a90dabc6828f3a798684 SHA-1: c550fb3c4dd8c33af27c3d4c2d55332f8ba1c97b SHA-256: 8524d24ea83c0c48cc594f6b89dd199bbcb2b779386e8c574215517d08fea129

140 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK

T1566.002 Spearphishing Attachment T1059.005 Visual Basic T1059.001 PowerShell

The critical heuristics OLE_XLM_AUTOOPEN and OLE_XLM_AUTOOPEN_DEFINEDNAME indicate the presence of an Excel 4.0 Auto_Open macro. ClamAV detection further confirms this as 'Doc.Downloader.EmotetExcel01220-9936774-0', a known Emotet downloader variant. The Auto_Open macro is designed to execute automatically when the spreadsheet is opened, serving as a loader for further malicious activity, typically downloading and executing a second-stage payload.

Heuristics 3

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.
ClamAV: Doc.Downloader.EmotetExcel01220-9936774-0 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Doc.Downloader.EmotetExcel01220-9936774-0
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.

Filename	Kind	Source	Size
`xlm_macros.txt` `c355a4e8b51815f97cf3e202ab7d47ce16f5f701c419b0e7a11ef751a8ea709e`	xlm-macro	oletools.olevba.extract_all_macros (XLM macro listing)	3661 bytes

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