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

Static analysis result for SHA-256 5ef88d3495be9535…

MALICIOUS

Office (OLE) / .XLS

50.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 2fdaa1717b7b249f1985389357133d66 SHA-1: de4cec1fdb7ebc03b147d1b4475f2dc748d4aa3f SHA-256: 5ef88d3495be9535725ae2949ef2442b678f76e90444075e17f71b944d9b1e33
222 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1071.001 Web Protocols

The sample is an Excel 4.0 macro-enabled spreadsheet that uses an Auto_Open macro to execute. It displays a DocuSign lure to encourage macro execution. The macro contains a formula that reconstructs the URL 'http://mahathi2.ondemandcreative.com/24.gif' and attempts to download a file to 'C:\ProgramData\Triol\explorer.exe'.

Heuristics 6

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • URL reconstructed from XLM cell array (1 URL) critical OLE_XLM_CELL_ARRAY_URL
    Excel 4.0 macro sheet stages its payload URL across the BIFF8 Shared String Table (one quoted-char SST entry concatenated with & at runtime) or across individual numeric cells (one ASCII charcode per cell). The reconstructed URL is invisible to literal-bytes URL extraction because it is never contiguous in the workbook stream. URLs were recovered by walking the BIFF8 record stream and decoding SST entries plus LABELSST/RK/NUMBER cells.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • 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://mahathi2.ondemandcreative.com/24.gifDa
    • http://mahathi2.ondemandcreative.com/24.gif�
    • http://mahathi2.ondemandcreative.com/24.gif

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
b85a04030ee15a5823afbe8a5c58782f7c760714b2f75fcf902d376138ea1320		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 2772 bytes

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