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

Static analysis result for SHA-256 73235ae56e1efecb…

MALICIOUS

Office (OLE) / .DOC

201.5 KB Created: 2020-04-02 13:52:08 Authoring application: Microsoft Excel
MD5: 1f78ceb92b9f458f84792aaf6088c778 SHA-1: 17bfe86a4c65e5a2c506e85be33c376b877c8f89 SHA-256: 73235ae56e1efecbfeffef7ab514af8c28b92fc4cc8a12970b96161dc7bc783e
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open entry, which is a common technique for executing malicious code upon opening the document. The macro sheet contains a dangerous formula API call, suggesting it is designed to run arbitrary commands. No specific family could be identified.

Heuristics 3

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
1890f228e9c8df87d37174a1839ec391c47c8fd3fa7a23dbb237c4b391db78f9
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 39932 bytes