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

Static analysis result for SHA-256 746a9efdf92bc2fd…

MALICIOUS

Office (OLE) / .XLS

272.0 KB Created: 2020-06-18 09:23:00 Authoring application: Microsoft Excel
MD5: 4252e679073f00b98a0e6173c3c42bfb SHA-1: 07e4f68a0c680d67773ac1806971353fdb20ac16 SHA-256: 746a9efdf92bc2fdbf2f9e4707052c50a7d0d6307afa9339c1a5e10e8d5ebf9d
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding. This indicates the workbook is designed to automatically execute a macro when opened. The presence of dangerous formula APIs like RUN further suggests malicious intent, likely to execute arbitrary commands. No specific IOCs were extracted, but the technique itself is a strong indicator of malicious activity.

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
fc02ac9c9b182319d9ffd7dc812cc3ded39855ef85d89593005291321d71a928
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 57722 bytes