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

Static analysis result for SHA-256 682413087b8e0563…

MALICIOUS

Office (OLE) / .DOC

174.5 KB Created: 2020-04-08 14:30:53 Authoring application: Microsoft Excel
MD5: 31b7114a6e14099983fcde997f5003bb SHA-1: b010517972dfaf427b335a2661bbeea56924505d SHA-256: 682413087b8e056322f877cd437532bbd2d68815708cbe1c6c86fbd84a32438d
100 Risk Score

Malware Insights

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

The file is an encrypted Excel 4.0 macro sheet, indicated by multiple heuristic firings including OLE_XLM_ENCRYPTED_MACROSHEET and OLE_XLM_AUTOOPEN. This suggests the document is designed to execute malicious macros upon opening. The presence of encrypted macros and the nature of XLM macros point towards a downloader or initial execution stage for further malicious activity.

Heuristics 3

  • Encrypted Excel 4.0 macro sheet high OLE_XLM_ENCRYPTED_MACROSHEET
    Workbook contains an Excel 4.0 macro sheet and BIFF FILEPASS encryption. Password-protected XLM macro sheets, especially the default Excel password path, are a common malware evasion pattern because static formula extraction may fail until the workbook is decrypted.
  • OLE metadata lists many Excel 4.0 macro sheets high OLE_XLM_DOCPROPS_MACROSHEET_INVENTORY
    Workbook contains a BIFF Excel 4.0 macro-sheet marker and its clear OLE DocumentSummaryInformation stream lists many MacroN sheet titles. This is a useful static signal when FILEPASS encryption prevents formula extraction from the workbook stream.
  • 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.