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

Static analysis result for SHA-256 7950d1f2a009e182…

MALICIOUS

Office (OLE) / .XLS

36.0 KB Created: 2020-11-25 10:44:37 Authoring application: Microsoft Excel
MD5: a36d2cf9ae1dd020733e0c50716ba98a SHA-1: 0faf1247baaefaa2e0cbb684d3d7b50a3d864fcb SHA-256: 7950d1f2a009e1829085e1f176ad8c915a11173d3a00da850e754d9da3a73e8d
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open function, which is a known method for executing malicious code upon opening the spreadsheet. The presence of dangerous formula APIs like RUN indicates an intent to execute arbitrary commands. While no specific URLs or hashes were extracted, the macro's execution capability is the primary threat.

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
3ecf6fef0cc4becc6c8d454425ba5c40054463ffb461a64e58696d0210563856
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6556 bytes