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

Static analysis result for SHA-256 fcc52a7b74234f2b…

MALICIOUS

Office (OLE) / .XLS

204.5 KB Created: 2021-02-23 19:31:34 Authoring application: Microsoft Excel
MD5: aa90be3c5a4884f818d76a9685c902df SHA-1: 412814a6bce30fc94281e9d164e66df31bf829c1 SHA-256: fcc52a7b74234f2b82261ec14255be12426d8a5087ac812b8832341fec39bb9b
60 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample is an Excel 4.0 macro sheet that is encrypted, as indicated by the OLE_XLM_ENCRYPTED_MACROSHEET heuristic. The OLE_XLM_AUTOOPEN heuristic further suggests that macros are present and likely intended for execution upon opening. Due to the encrypted nature of the macro sheet, the specific actions it performs cannot be determined, but it is highly probable that it attempts 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.