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

Static analysis result for SHA-256 9fb0ab19a644d7d3…

MALICIOUS

Office (OLE) / .XLS

195.0 KB Created: 2021-02-23 19:30:51 Authoring application: Microsoft Excel
MD5: a9b4ce45a056bfde65a0dd2bb984a991 SHA-1: c75ecbe59c3d11b050e83ed4e9b155500e0ff234 SHA-256: 9fb0ab19a644d7d30af237e4cf718cac73b51d1c06dc61d57c34b059681ed07f
60 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 the OLE_XLM_ENCRYPTED_MACROSHEET heuristic. The presence of an OLE_XLM_AUTOOPEN heuristic suggests that the macro is designed to execute automatically upon opening the spreadsheet. The document body is heavily obfuscated and unreadable, preventing further analysis of its specific intent. However, the combination of an encrypted macro sheet and auto-execution points towards 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.