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

Static analysis result for SHA-256 0504efbd8716d561…

MALICIOUS

Office (OLE) / .XLSX

129.5 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: d094f81230cb89815e5de07916f4f50d SHA-1: 0d0749fe1659ce7b1f1c1bf97cfd0c0e8e3c1993 SHA-256: 0504efbd8716d561d5409deb3e2b4510216bbde1998c01b527435cabde0bbc96
300 Risk Score

Malware Insights

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

The sample contains a Workbook_Open VBA macro that is heavily obfuscated and uses CreateObject to instantiate Wscript.Shell. This script is designed to download and execute a second-stage payload from a list of URLs, including 'http://santafe.com/el-image/U0vTPAZcEGBcEGF' and 'http://blute.com/3dtech/jLu8IAnnj3gK9WC/'. The macro also attempts to drop files named 'yhjlswle.vbs' and 'ughldskbhn.bat' into the 'c:\programdata' directory.

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