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

Static analysis result for SHA-256 a2bbc8aee45c89cd…

MALICIOUS

Office (OLE) / .XLS

174.0 KB Created: 2020-11-10 04:26:51 Authoring application: Microsoft Excel
MD5: 6a28b8ba86a36edae96f1169c5ba0871 SHA-1: 557821bb1a986882a3c3245462c00cb94af41782 SHA-256: a2bbc8aee45c89cd40cb00da3d0e0c8d0e3503423d5bcbee6e0077fab43ce0ab
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 document body is heavily obfuscated and unreadable, preventing further analysis of its specific intent. However, the combination of encryption and auto-execution points towards a malicious downloader or dropper.

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.