Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 c857d84863251909…

MALICIOUS

Office (OLE) / .XLS

70.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-05-03
MD5: df076d0f45a4e3e23be2b69d624ccf02 SHA-1: 80bc67c8e985b562b4972862d69132885936945b SHA-256: c857d848632519091caa6d0ea22c4a725f2ee28029f2f087ebf6cb05b074f805
200 Risk Score

Malware Insights

Emotet · confidence 95%

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

The file is an Excel 4.0 macro-enabled spreadsheet detected as Emotet by ClamAV. It contains an Auto_Open macro that utilizes dangerous formula APIs, specifically the RUN function, to download and execute a payload. The macro attempts to download from multiple URLs, including http://ecoarch.com.tw/cgi-bin/E/, and save the payload as a .exe file in the System32 directory.

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-b3c5cc3b13c03bcc-9950246-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-b3c5cc3b13c03bcc-9950246-0
  • 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
023eece581745d86e8a881663e496cab25dc20dc1e2c24ba47f1be10064b9c6f
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6827 bytes