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

Static analysis result for SHA-256 7847c9c6eae9fb7c…

MALICIOUS

Office (OLE) / .XLS

153.0 KB Created: 2020-04-23 12:26:24 Authoring application: Microsoft Excel
MD5: b39a1365b5ba8cb5ed52942148636bf1 SHA-1: 189509ee51aae87f21188cf75c1785207a92ec54 SHA-256: 7847c9c6eae9fb7ca70174ed2092cd46f3d8b5c3172a980446aecf0d28961430
100 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample is an Excel file containing encrypted Excel 4.0 macros, as indicated by multiple high-severity heuristic firings. The presence of an 'AUTOOPEN' macro suggests that malicious code is intended to execute automatically when the spreadsheet is opened. The document body is heavily obfuscated and truncated, preventing a more detailed analysis of its specific purpose.

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.