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

Static analysis result for SHA-256 46043fd12662667c…

MALICIOUS

Office (OLE) / .XLS

49.0 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 0d55b87f0ad0b156aba71327e4fdb97a SHA-1: 72024ed873120ec9525bfdb595f958cac2e9413e SHA-256: 46043fd12662667c240504005e341e1900a25e39e83379bb770da0e7e609844e
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1566.001 Spearphishing Attachment

The sample is an Excel file containing Excel 4.0 (XLM) macros, specifically an Auto_Open defined name. This indicates that the macro will execute automatically when the workbook is opened. The heuristics indicate the use of dangerous formula APIs, including the RUN function, which is commonly used to execute arbitrary code or download further payloads. No specific URLs or hashes were extracted, but the presence of Auto_Open with the RUN function is a strong indicator of malicious intent.

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
4b44cf75ee6c9a16ca90d00d74bb513e0a252cb47e302a6893322b291a168274
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 13233 bytes