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

Static analysis result for SHA-256 5a9c247eb66309ac…

MALICIOUS

Office (OLE) / .XLSX

138.0 KB Created: 2022-02-09 09:48:26 Authoring application: Microsoft Excel
MD5: 82a7636350990f386421f92fcde99ec0 SHA-1: 92ccfbd4fdad66256f523167ba2c66429b99c70d SHA-256: 5a9c247eb66309ac65a39e883d203b32bdce21170824e0a3e54eab8ba7305ccd
262 Risk Score

Malware Insights

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

The sample contains a Workbook_Open VBA macro that utilizes CreateObject to download payloads from multiple URLs. The macro's functionality is to download and execute a second-stage payload, as indicated by the 'OLE_VBA_CELL_DROPPER_URL' heuristic and the embedded URLs. The ClamAV detection of 'Doc.Downloader.EmotetRed02220-9938909-0' further supports its role as a downloader.

Heuristics 7

  • 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.Downloader.EmotetRed02220-9938909-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.EmotetRed02220-9938909-0
  • 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://midnightsilvercrafters.com/store/wBjNOUw/
    • http://tempral.com/NATE_05_22_2009/BI710N4cQ6R3/
    • https://redington.karmatechmediaworks.com/wp-content/3JVuVx7QUM/
    • https://uhc.karmatechmediaworks.com/wp-content/0EqfdeznntlOpaIP2Qv/
    • https://servilogic.n
    • https://comezmuhendislik.com/ljfrmm/VTpHRFWoORAHnRQ3aQL/
    • http://webmail.glemedical.com/wp-content/J1M2xxodH/
    • http://toto.karmatechmediaworks.com/wp-content/i826vbcVgRJ/
    • https://golfpia.karmatechmediaworks.com/wp-content/oEicpDnEkk/
    • https://garyjharris.com/cgi-bin/0hH/
    • https://vietnam.karmatechmediaworks.com/wp-content/PfSVQagusZy7AaMw/
    • https://vinculinc.karmatechmediaworks.com/wp-content/VlcOPPwgidWlXDJNs6/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
86bc82c145e12ebd70c392766ad10c3ecce1c8bdc6cab5f18da2f009cd030ace
vba-macro oletools.olevba.extract_macros (decoded VBA source) 52352 bytes