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

Static analysis result for SHA-256 850a0a59c72d5ae2…

MALICIOUS

Office (OLE) / .XLS

39.5 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: cf12795609fa58b5677b04d9f85a8ae5 SHA-1: 305f939fc48b4dd967cba7a081a13bf4c5204a8e SHA-256: 850a0a59c72d5ae2c93a82aee4f1825a4c54ef8fbc32c490137f39057bfd4d2e
160 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

The file is an Excel 4.0 macro-enabled spreadsheet. Heuristics indicate the presence of an Auto_Open macro that uses dangerous functions, specifically the RUN function, which is often used to execute arbitrary code. The macro attempts to download a file from 'wnxlxjw10whta03ytgdi.com/inda.xls' using a reconstructed CALL formula. This strongly suggests a downloader or droppper functionality, where the downloaded file is likely a malicious payload.

Heuristics 4

  • 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.
  • 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
d4018ec89a5b54693089f4c51f9abe6ccc20d8f86a31de96db8816e0d152535d		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 2417 bytes

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