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

Static analysis result for SHA-256 7ba1a1d1e7e3c15d…

MALICIOUS

Office (OLE) / .XLSX

129.5 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: d0f6829eb4902844669d449e1208daa1 SHA-1: 4db49e7adcd6d3f93d8f07e2e96198970b2560e8 SHA-256: 7ba1a1d1e7e3c15d56b14ac41ad31e957937373bcaccbc4b49a28d911a77cb4b
300 Risk Score

Malware Insights

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

The sample contains an obfuscated VBA macro loader that executes upon opening the workbook. This macro utilizes `CreateObject` and `Wscript.Shell` to download and execute a second-stage payload from a list of URLs, saving it as a VBScript and a batch file in the programdata directory. The presence of `Wscript.Shell` and the download functionality strongly indicate a downloader pattern.

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