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

Static analysis result for SHA-256 d9d886c7e84a45b9…

MALICIOUS

Office (OLE) / .XLS

36.5 KB Created: 2020-11-30 13:15:17 Authoring application: Microsoft Excel
MD5: 5783e27ec37d93acf17f875761d309cf SHA-1: cdcb50b28bf09540036aab8a82422db4673b3d96 SHA-256: d9d886c7e84a45b9d787e98ecb696339679ca344764d8bc569a049bc2a9bec27
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled spreadsheet. Heuristics indicate the presence of an Auto_Open macro, which is a common technique for executing malicious code upon opening the document. The critical heuristic 'OLE_XLM_DANGEROUS_FN' specifically flags the use of dangerous formula APIs like 'RUN', suggesting the macro is designed to execute arbitrary commands. No specific URLs or hashes were extracted, but the presence of the Auto_Open macro is a strong indicator of malicious intent for initial payload delivery.

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
066f03fe44c1f16fe77fd60157f63818039d0f455062b81f1de74d5b41aec9d7
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6541 bytes