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

Static analysis result for SHA-256 421cccf7ef2ecd48…

MALICIOUS

Office (OLE) / .XLS

155.5 KB Created: 2020-04-23 12:26:24 Authoring application: Microsoft Excel
MD5: 14637642c8cfe797f2683f2bd463eb2f SHA-1: ec47c4eceb2710e9deb8c3b17e2135e75a537e1a SHA-256: 421cccf7ef2ecd482467b2f470a28707447c39d581d11e39578f4dba4472fd71
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 OLE_XLM_AUTOOPEN heuristic further suggests the presence of an auto-executing macro. While the document body is heavily obfuscated and unreadable, the presence of encrypted macros strongly suggests a malicious intent, likely to execute arbitrary code or download further stages. No specific IOCs were extracted due to the obfuscation.

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.