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

Static analysis result for SHA-256 735742eb45eba996…

MALICIOUS

Office (OLE) / .XLS

64.5 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: f166a09de0b4b4dc03545826aa756530 SHA-1: 040f89e78527e08b0e18c351a3ee7e3e943a41e9 SHA-256: 735742eb45eba99688ab1f2e1123de8833226c9c98ce5acd8f0d28e9bbb930de
100 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic

The sample is an Excel 97-2003 Workbook containing an Excel 4.0 macro sheet with an Auto_Open entry. The macro sheet contains a string that, when executed, constructs and runs a command to download a payload from a hardcoded URL. The document body also contains a lure to enable macros, which is a common tactic for macro-based malware.

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