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

Static analysis result for SHA-256 6b65f94cb0c24235…

MALICIOUS

Office (OLE) / .XLSX

31.0 KB Created: 2021-01-25 16:11:57 Authoring application: Microsoft Excel
MD5: 0175fdc8953ea17e1fcbba8df3576c8d SHA-1: 0ccb3e431c4b4255577a959d0e499398ed2ce20f SHA-256: 6b65f94cb0c24235644695272305efd7c7001d0617ea92ddd5a407ae1f06fc17
160 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 macros, specifically an Auto_Open macro. The document body explicitly instructs the user to 'Enable Editing' and 'Enable Content', a common lure to bypass macro security. The presence of the Auto_Open macro and the lure strongly suggests a malicious intent to execute arbitrary code upon opening.

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.
  • 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.
  • 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
6ae16315470b988b71287825183adae0297182d510fc9ab20204c427b38ae8eb
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 3297 bytes