Emotet — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 071791890a8d7607…

MALICIOUS

Office (OLE) / .XLSX

129.5 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 8729855c7ec1bc4fcf73d318b7fc86e9 SHA-1: 7d517f53c099fa3767ff92f45400d4a1b5bc10fb SHA-256: 071791890a8d76077c6fe240dc85ee8195a23a76933e20e9188bcc8b30a441f3
300 Risk Score

Malware Insights

Emotet · confidence 95%

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

The sample contains heavily obfuscated VBA macros, including a Workbook_Open auto-exec loader, which is characteristic of Emotet. The script uses CreateObject and ShellExecute to download and execute a second-stage payload from a list of URLs. The reconstructed URL is "http://santafetortillala.com/_baks/tUX9/ ,http://donbaham.com/Home_files/YS0PazXcyeraes/,http://barnhart-studies.com/eln-images/Vcbhg1nb/,http://zenzebra.net/plath/9Q0DBle/,http://blute.com/3dtech/jLu8IAnnj3gK9WC/,http://miniflam.com/eln-images/fSwbQjUMAfGxdw/,http://marezdecor.com/MarezGallery/sEQxWTPj7CA8ratY/,http://realacorp.net/PhotoGallery/UwRHgceSGbaCeGF/,http://miniflam.com/eln-images/u0vT/,http://blute.com/3dtech/jLu8IAnnj3gK9WC/,http://marezdecor.com/MarezGallery/sEQxWTPj7CA8ratY/,http://realacorp.net/PhotoGallery/UwRHgceSGbaCeGF/,http://zenzebra.net/plath/9Q0DBle/,http://barnhart-studies.com/eln-images/Vcbhg1nb/,http://donbaham.com/Home_files/YS0PazXcyeraes/,http://santafetortillala.com/_baks/tUX9/". The script also attempts to drop files to c:\programdata\yhjlswle.vbs and c:\programdata\ughldskbhn.bat, indicating a downloader and dropper functionality.

Heuristics 7

  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
  • ClamAV: Doc.Downloader.EmotetRed02220-9938909-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.EmotetRed02220-9938909-0
  • Reference to Windows Script Host high SC_STR_WSCRIPT
    Reference to Windows Script Host
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
7a075e02dc1e88807280b9b84946715e79a3c091d50391301434649c77b78ea1
vba-macro oletools.olevba.extract_macros (decoded VBA source) 12808 bytes