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

Static analysis result for SHA-256 a4eb392b6e704813…

MALICIOUS

Office (OLE) / .XLS

76.0 KB Created: 2020-12-15 12:07:20 Authoring application: Microsoft Excel
MD5: 658218f13b6ab9515c7fd2e8ebdfdb8b SHA-1: cd9198c71fa9ab2494a0872f37fbb1b1ecafea34 SHA-256: a4eb392b6e704813b2454cb01eb04999ad2ad755d8b6322e28c2652796049e8e
60 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample is an encrypted Excel 4.0 macro sheet, indicated by the OLE_XLM_ENCRYPTED_MACROSHEET heuristic. The presence of an AUTOOPEN macro (OLE_XLM_AUTOOPEN) suggests that the macro sheet is designed to execute automatically upon opening the document. The document body is heavily obfuscated and unreadable, providing no direct clues about the payload. However, the combination of encrypted macros and an auto-execution trigger strongly implies a malicious intent, likely to download and execute a secondary payload.

Heuristics 2

  • 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.
  • 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.