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

Static analysis result for SHA-256 7606540e16897601…

MALICIOUS

Office (OLE) / .XLSX

121.0 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 587fec04524967dee47377d6ef00858b SHA-1: cf87aba0cb07ba6abf06aa482a6d5e10dea2ab03 SHA-256: 7606540e168976011dafd8e2fe351b406a583b7b60757a804c69a00ff067d3f1
302 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample is a malicious Excel file containing a Workbook_Open VBA macro. This macro is designed to execute a series of commands, including the creation of a VBScript file and a batch file in the 'programdata' directory. The macro also attempts to download payloads from multiple embedded URLs, indicating a downloader functionality. The ClamAV detection of 'Xls.Downloader.Emotet' further supports this assessment.

Heuristics 8

  • URL reconstructed from VBA cell-staged base64 dropper (7 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: Xls.Downloader.Emotet-ab81c42b2bd4747e-9951196-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-ab81c42b2bd4747e-9951196-0
  • 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://lbsbriefs.com/cgi/2kl8X826xEKeuhI/
    • http://howebeautiful.com/eln-images/tyj208/
    • http://lazylargomotels.com/cgi/wZrYbJ/
    • http://sleepstarlite-ozark.com/batesville/UjX/
    • http://osaka.musicaldog.com/05-set/YLBOd/
    • https://egemenrulman.com/Fox-C404/qrr2OCShGJGH06Gm/
    • http://skyridgedesigns.com/eln-images/38pr2cu3xt2Ai/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
faf50200d5a9adeeda00cc1da1bbf8f6abf0317a1e97a58db8ae804ba12ba446
vba-macro oletools.olevba.extract_macros (decoded VBA source) 13985 bytes