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

Static analysis result for SHA-256 6b1e310a45e32a12…

MALICIOUS

Office (OLE) / .XLSX

145.5 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 59b0ec0503aa72090f7bde6eebd6db36 SHA-1: a4fd02dd2399bc50cecf54e487f8e52b39b3985d SHA-256: 6b1e310a45e32a12311dc350bdecfdc1267d976b9252076db01083429cdf9a34
302 Risk Score

Malware Insights

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

The sample contains VBA macros that trigger on Workbook_Open, indicative of malicious intent. These macros are designed to reconstruct and download payloads from a list of URLs, such as 'http://reumatismclinic.com/-/scCnm3mbJRpsaBKBbrC/'. The use of CreateObject and Wscript.Shell further suggests the execution of downloaded content, likely a second-stage malware. The ClamAV detection and heuristic firings confirm its malicious nature.

Heuristics 8

  • URL reconstructed from VBA cell-staged base64 dropper (12 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.Malware.Valyria-10004384-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Valyria-10004384-0
  • 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 http://reumatismclinic.com/-/scCnm3mbJRpsaBKBbrC/
    • https://shodhmanjari.com/wp-admin/xjEmK4Pd3N/
    • http://tubelocal.net/wp-admin/X4Xm4Mk/
    • https://pacifichomebroker.com/roderick/RRk/
    • https://molinai-journal
    • https://marineboyrecords.com/font-awesome/QBBByHDDYl0slxlQ/
    • https://mashuk.net/wp-includes/ej6R4fkU/
    • https://lapalette.store/Fox-C404/Gngia6hD0i5zsgd2/
    • https://jhonnycryptic.com/cgi-bin/OhZdKCDRBYGZudqs/
    • https://korean911.com/wp-admin/TZczIsZtMFXxM5T/
    • https://fonijuk.org/wp-content/fzq6vYFUMEiRoR8vG/
    • https://baltoe.blog/-/6IC/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
527d0656a0c2c323955d068683ef8f7e20c035cda247a1e24383595c0eb3403b
vba-macro oletools.olevba.extract_macros (decoded VBA source) 7821 bytes