Emotet — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 0af3d4cdf842ee68…

MALICIOUS

Office (OLE) / .XLSX

121.0 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 4ff8fdbdeaf0f0ed5e3ba7219ad3f811 SHA-1: 0bed2512ad0792f41fc8dc95be88488a65802309 SHA-256: 0af3d4cdf842ee68c64136a90764758b1258b8162767f70b2a4fe31f1176edb6
240 Risk Score

Malware Insights

Emotet · confidence 95%

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

The file contains a Workbook_Open VBA macro that utilizes CreateObject to execute Windows Script Host, likely to download and run a second-stage payload. The macro attempts to construct a command line that includes a PowerShell execution command with a Base64 encoded string, which decodes to multiple URLs. These URLs are likely sources for the malicious payload. The ClamAV detection and heuristic firings strongly indicate Emotet.

Heuristics 6

  • ClamAV: Xls.Downloader.Emotet-ab81c42b2bd4747e-9951196-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-ab81c42b2bd4747e-9951196-0
  • 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
faf50200d5a9adeeda00cc1da1bbf8f6abf0317a1e97a58db8ae804ba12ba446
vba-macro oletools.olevba.extract_macros (decoded VBA source) 13985 bytes