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

Static analysis result for SHA-256 440496a116ae475c…

MALICIOUS

Office (OLE) / .XLS

153.0 KB Created: 2020-04-23 12:26:24 Authoring application: Microsoft Excel
MD5: cab7720d67d7700d40b24fee321734ce SHA-1: cb22de552873492e9925853b3cb7ad2ad5a00e8c SHA-256: 440496a116ae475c19a8a00af2b51c05c6a62040c4ec556fc7e7788682962be6
100 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications

The sample is an encrypted Excel 4.0 macro sheet, indicated by multiple high-severity heuristic firings. The presence of an 'AutoOpen' macro suggests it attempts to execute automatically upon opening. The document body is heavily obfuscated and truncated, preventing a detailed analysis of its specific payload or intent. However, the macro sheet structure strongly implies malicious macro execution.

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.