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

Static analysis result for SHA-256 16479a5943109d38…

MALICIOUS

Office (OLE) / .XLS

380.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: 9200d16a2ccc48bc3a2c4057a720318f SHA-1: 51c367989953f4e83f38de76143330c19785ac65 SHA-256: 16479a5943109d38d3508cf066b422c19fc657bc8ab264d087aad5d927401fc1
102 Risk Score

Malware Insights

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

The sample is an Excel file containing Excel 4.0 (XLM) macros, indicated by the OLE_XLM_AUTOOPEN heuristic. The document also contains a lure to enable macros, a common tactic for malware droppers. The XLM macros likely download and execute a second-stage payload from one of the embedded URLs, such as https://caiogabriel.com.br/tOKLlSLW/lena.html or https://bwctradex.com/BcotoLXTr1y/lena.html, using tools like rundll32.exe or regsvr32.exe.

Heuristics 4

  • 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.
  • 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://caiogabriel.com.br/tOKLlSLW/lena.html
    • https://bwctradex.com/BcotoLXTr1y/lena.html

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
d46ad6b52df62d280ddc3eb28f4fdfc78bc84dc99077b9aa50809affc4be6057
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8812 bytes