Malicious Office (OLE) / .XLSX — malware analysis report

Static analysis result for SHA-256 11c944369c864e64…

MALICIOUS

Office (OLE) / .XLSX

129.5 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 0455068d5be8d44fa7ecff9a02418f24 SHA-1: 5ba169a7245487c6e732202a27676ce0d6bb6cd2 SHA-256: 11c944369c864e649f280e5450006905c3e88d37313cc1dc8f1134e6944666cc
300 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1105 Ingress Tool Transfer

The sample is a malicious Excel document containing an obfuscated VBA macro loader. The macro executes a series of commands that download and save two files, 'yhjlswle.vbs' and 'ughldskbhn.bat', to the 'c:\programdata\' directory. The VBA code also attempts to construct a URL from concatenated strings, which resolves to 'http://santoetortilla.com/_baks/tUX9/'. This indicates the macro's primary purpose is to download and execute a second-stage payload.

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

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