Emotet — Office (OOXML) / .XLSX malware analysis

Static analysis result for SHA-256 0051d3f00b7b9eb2…

MALICIOUS

Office (OOXML) / .XLSX

92.0 KB Created: 2015-06-05 18:17:20 UTC Authoring application: Microsoft Excel 12.0000
MD5: 2a386413b24fe308e7a50fa12ddec2de SHA-1: 35e183c6133e0106072dac47c147d0b8988e7483 SHA-256: 0051d3f00b7b9eb242845ef1c813da0c6c597e33168a15ff60112773ff3b6944
260 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1059.003 Windows Command Shell T1105 Ingress Tool Transfer

The sample is an Excel document containing obfuscated VBA macros designed to execute a malicious payload. The Workbook_Open macro and CreateObject calls indicate an automated execution flow. The script attempts to download and execute files from multiple URLs, including 'http://harperhoproducts.com/Merchandise2/ARSf1LICoauhH1rDiH/', and writes them to 'c:\programdata\yhjlswle.vbs' and 'c:\programdata\ughldskbhn.bat'. ClamAV detection further confirms its malicious nature as Emotet.

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
c7f6d66bcf19a7a8c9a74693526ab13446a2bbf6e601eed06efbe33f0860381c
vba-project OOXML VBA project: xl/vbaProject.bin 37888 bytes