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

Static analysis result for SHA-256 4f8dd23c570f41dd…

MALICIOUS

Office (OLE) / .XLSX

31.0 KB Created: 2021-01-25 15:54:11 Authoring application: Microsoft Excel
MD5: ac6f4320902c16f70b54a2d2a3ce0691 SHA-1: 45f3c1f42a6bac98d95432d0fc131571ca6c6afe SHA-256: 4f8dd23c570f41dd6905cf959381a860c330c1ae492e49bee1f81a5ecd07874a
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 User Execution: Malicious File T1059.005 PowerShell

This Excel 4.0 macro-enabled spreadsheet contains an Auto_Open macro, a known technique for executing malicious code upon opening. The document body explicitly instructs the user to 'Enable Editing' and 'Enable Content', indicating a social engineering lure to bypass security measures. The presence of dangerous formula APIs within the XLM macro further supports its malicious intent, likely to download and execute a secondary 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
53eafd29a153b7b300e4133c406fe6eacaba80db3f30cbf2e9c9368481f1e884
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 3444 bytes