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

Static analysis result for SHA-256 f1af3e2e0b9c7568…

MALICIOUS

Office (OLE) / .XLS

65.3 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: e9abe6a9bf4f7823a1347383e0c4d792 SHA-1: 792ecbfa1173e691287443e5af2a516441796c5b SHA-256: f1af3e2e0b9c7568cb5b14e08f48571cef8e738b6a8155739c6a1df2a52a029d
100 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious Link: Malicious File

The sample is an Excel 4.0 macro sheet that contains an Auto_Open macro. This macro is configured to execute a command that downloads a payload from the reconstructed URL 'http://0xc12a24f5/cc.html'. The document body explicitly instructs the user to 'Enable Editing' and 'Enable Content', which is a common lure to bypass security measures and execute malicious macros.

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