Emotet — Office (OOXML) / .XLSX malware analysis

Static analysis result for SHA-256 8678216ccb71d2a9…

MALICIOUS

Office (OOXML) / .XLSX

115.1 KB Created: 2015-06-05 18:17:20 UTC Authoring application: Microsoft Excel 12.0000
MD5: ca7d951f605334242631c892623816eb SHA-1: 9fb248c10d642d4d5b36604f6824e3200c378a93 SHA-256: 8678216ccb71d2a9a7c1aa5199daa35250880bd3418a4705e58c37f036e8008c
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample contains a Workbook_Open macro that uses CreateObject to execute obfuscated PowerShell commands. The PowerShell command attempts to download a payload from multiple URLs, including 'http://sumedahoonline.com/wp-content/HyzNXJ30XQEVcBSbRH/'. The presence of a Workbook_Open macro and the obfuscated PowerShell execution are strong indicators of Emotet activity.

Heuristics 5

  • ClamAV: Xls.Downloader.EmotetExcel02223-9938902-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.EmotetExcel02223-9938902-0
  • 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 project inside OOXML medium OOXML_VBA
    Document contains a VBA project — VBA macros present

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
df1eb14c222394595c0518b49eec2b55ed9573146c5f1717dedceddd2e199a2b
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 12041 bytes
vbaProject_00.bin
f7a0a39629174a0ea53bfc57f5dd0e99036be5f81b107eee6bebe74bf9a2119e
vba-project OOXML VBA project: xl/vbaProject.bin 42496 bytes