Emotet — Office (OOXML) / .XLSX malware analysis

Static analysis result for SHA-256 1935c5c124f52faa…

MALICIOUS

Office (OOXML) / .XLSX

92.0 KB Created: 2015-06-05 18:17:20 UTC Authoring application: Microsoft Excel 12.0000
MD5: ac61acb75b67a45100f7f6817ea7154d SHA-1: 3ce5dab8e89071a0afa4c09742a8c407ae91d0d8 SHA-256: 1935c5c124f52faae27ee9e41016e342798f47d44e90483b6104effa4a6f4d1b
260 Risk Score

Malware Insights

Emotet · confidence 95%

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

The sample is an Excel file containing obfuscated VBA macros, specifically a Workbook_Open auto-execution loader. The macros utilize CreateObject to execute shell commands, which are designed to download and run a VBScript payload from a list of hardcoded URLs. ClamAV detection confirms this as an Emotet variant, a known downloader.

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
df4859b952c1a82eb824fc2ab0da33b2f4e32ef647930612bdb243992722876e		 vba-project OOXML VBA project: xl/vbaProject.bin 37888 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.