Emotet — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 5a493ef83995ac06…

MALICIOUS

Office (OLE) / .XLSX

129.5 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 012286a7b1f0845b62acf5f371480346 SHA-1: 50c8baadd8b5a3f358b3a1b24d9443a4f61893bb SHA-256: 5a493ef83995ac06cf339bac07a8fe0902360414d23b3fc38c3e2877c74e3df4
300 Risk Score

Malware Insights

Emotet · confidence 95%

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

The sample is a malicious Excel document containing obfuscated VBA macros. The Workbook_Open macro utilizes CreateObject to instantiate Wscript.Shell, which is then used to execute a downloaded payload. The script attempts to download payloads from multiple URLs, including reconstructed URLs like 'http://santoetortillla.com/_baks/tUX9/' and 'http://donbaham.com/Home_files/YS0PAPxYerae/', and saves them as 'yhjlswle.vbs' and 'ughldskbhn.bat' in the 'c:\programdata\' directory. The ClamAV detection name 'Doc.Downloader.EmotetRed02220-9938909-0' strongly suggests the Emotet family.

Heuristics 7

  • 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: Doc.Downloader.EmotetRed02220-9938909-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.EmotetRed02220-9938909-0
  • 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
7a075e02dc1e88807280b9b84946715e79a3c091d50391301434649c77b78ea1
vba-macro oletools.olevba.extract_macros (decoded VBA source) 12808 bytes