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

Static analysis result for SHA-256 cc943068d8c70f86…

MALICIOUS

Office (OLE) / .XLS

218.5 KB Created: 2020-10-07 11:26:26 Authoring application: Microsoft Excel
MD5: 994edc9ad3264abc1cf4bade1eda6f2a SHA-1: 2aee1be5c5f016d320296c7d123a059c3afaed3f SHA-256: cc943068d8c70f865fb56396e252bea8af91565d35ac98bee78f9e7ae96c14ba
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 auto-open macro (OLE_XLM_AUTOOPEN) suggests it is designed to execute automatically upon opening. The encrypted nature and lack of readable document body text point towards a malicious intent, likely to download and execute a secondary payload, though the specific mechanism is obscured.

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.