Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 db606ab69b263ca5…

MALICIOUS

Office (OLE) / .XLS

73.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-05-17
MD5: c64292e4b093228141d3531fc50d3faf SHA-1: eacc3c8c7cbdc3ec385615c7485ada4c5cc09af4 SHA-256: db606ab69b263ca51c4b5148f7bd8388278a4954234bd1dbe70bfb358e77420a
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059.001 PowerShell T1105 Ingress Tool Transfer

The file is an Excel 4.0 macro-enabled spreadsheet. Heuristics indicate the presence of an Auto_Open macro that utilizes dangerous functions, specifically the RUN function. The macro constructs a URL by concatenating strings: "http" & "s://" & "hqisistemas.com.ar/cgi-bin/FMPTFCP/" and others, which are then used to download and execute a second-stage payload, likely a Windows executable. The ClamAV detection further confirms its malicious nature as Emotet.

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-ea85857e7e81817a-9950241-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-ea85857e7e81817a-9950241-0
  • 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
9aad8521d90ca7f536d86e805137dbff97d82a2ac842ee968dd491451c1e0d83
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6831 bytes