Emotet — Office (OOXML) / .XLSX malware analysis

Static analysis result for SHA-256 0d02389a32893bc7…

MALICIOUS

Office (OOXML) / .XLSX

92.0 KB Created: 2015-06-05 18:17:20 UTC Authoring application: Microsoft Excel 12.0000
MD5: e60444af47381a0f2e1f3380a164fe2b SHA-1: 5eda545d4c8c082ecd03648a5c8a0c6573fb3996 SHA-256: 0d02389a32893bc73f5c28e3b9fe5d8a49bc9bf0e4e13fb717963b1db0bfffff
260 Risk Score

Malware Insights

Emotet · confidence 95%

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

The sample contains a Workbook_Open macro that uses CreateObject to execute obfuscated VBA code. This code appears to download and execute a second-stage payload from a list of concatenated URLs, including 'http://harperhoproducts.com/Merchandise2/ARSf1LIcOauhH1rDiH/'. The ClamAV signature 'Xls.Downloader.EmotetRed02221-9938910-0' strongly suggests Emotet family activity.

Heuristics 6

  • 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: Xls.Downloader.EmotetRed02221-9938910-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.EmotetRed02221-9938910-0
  • 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
de7bcbc45ff0a77d05d9af662bacc316e71be11a980e94f6673e556a5dd9d1bc
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 12808 bytes
vbaProject_00.bin
070c9294d4c5b47fcc34921a625b19c7364fa364826bf9d6b453682401d98d62
vba-project OOXML VBA project: xl/vbaProject.bin 37888 bytes