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

Static analysis result for SHA-256 df1a2b784203a1c4…

MALICIOUS

Office (OLE) / .XLS

42.0 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: ac1dca9ee2e3866002eee92a1ade55d4 SHA-1: 76e92bfed7bd150af39b4e3acb24a739cb92b235 SHA-256: df1a2b784203a1c43c400e686c9caee56feb6bad649a6ecf2a87df99d33ad8ab
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1059.001 PowerShell

The critical heuristics indicate the presence of Excel 4.0 macros, specifically an Auto_Open defined name, which is a known method for executing malicious code upon opening the spreadsheet. The macro sheet itself contains references to dangerous formula APIs like RUN, suggesting it is designed to execute arbitrary commands. No specific family could be identified, but the technique is common for initial execution.

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
cb0c0cbdae8cb2995cc35a70fb663664ee4d1951d66c8840249b481bc6fb50d5
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8201 bytes