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

Static analysis result for SHA-256 00e27f49734eb87f…

MALICIOUS

Office (OLE) / .XLSX

36.0 KB Created: 2020-11-25 10:38:03 Authoring application: Microsoft Excel
MD5: 6b340add909f496cf97c6c150d8e84e4 SHA-1: b31806009f90ba990afe68d8d640be071ba94020 SHA-256: 00e27f49734eb87f409ecfbfd29ca50cbb680c382c4c9fc294420d441d139e96
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open entry, which is a known technique for executing malicious code. The `RUN=0` value associated with a dangerous formula API suggests the macro is designed to execute an external command. While no specific URL or command was directly extracted, the Auto_Open macro is a strong indicator of a downloader or initial execution stage.

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
6e049e668dcb10f0d3827e4cafda90ed97f015fb1ce719425b7c1a8638a4be76
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6421 bytes