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

Static analysis result for SHA-256 b29caf4fc7882262…

MALICIOUS

Office (OLE) / .XLS

268.0 KB Created: 2020-09-14 21:28:14 Authoring application: Microsoft Excel
MD5: 430c60b6ac9eba588f6ea8eda79e3f1f SHA-1: af64318bf3ba6d463f7e9f18d6a063ca007efdb2 SHA-256: b29caf4fc788226248bde8a634b3db30b3be68ce2892f0b737b9d71d9aef137c
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 OLE_XLM_AUTOOPEN heuristic suggests that the macro sheet is designed to run automatically upon opening the spreadsheet. The document body is heavily obfuscated and unreadable, preventing further analysis of its specific intent. However, the combination of encrypted macros and auto-execution points to a malicious downloader or initial access mechanism.

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.