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

Static analysis result for SHA-256 8c2b1a4145610445…

MALICIOUS

Office (OLE) / .XLS

65.4 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: 54644700e89ac0d0c49d3bbce02a0fc6 SHA-1: 6f9adf8e790547933e3a301bed413cd47e3c46a9 SHA-256: 8c2b1a41456104451d2166396e941e30159bef0a0d144ce50c3110f51c26009d
100 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious Link: Malicious File T1566.001 Phishing: Spearphishing Attachment

The sample is an Excel 4.0 macro-enabled spreadsheet. It contains an Auto_Open macro that executes a command to download a payload from the reconstructed URL 'http://0xc12a24f5/cc.html' using mshta. The document body also contains a lure to enable macros and editing, which is a common technique for macro-based malware delivery.

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