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

Static analysis result for SHA-256 737829a44edd7a28…

MALICIOUS

Office (OLE) / .XLS

31.0 KB Created: 2021-01-28 11:57:59 Authoring application: Microsoft Excel
MD5: 2f93163815bbb79858982b4f177cd55d SHA-1: a50aecc66e8171aa68db9cd03c3c6c67e289c193 SHA-256: 737829a44edd7a286225b68ede4ae92cba1ebf188e98a82fa6332b28b5ba8739
160 Risk Score

Malware Insights

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

The sample is an Excel 4.0 (XLM) macro-enabled spreadsheet. It contains an Auto_Open macro that uses dangerous formula APIs, indicating it is designed to execute malicious code. The document body explicitly instructs the user to enable content, a common lure for macro-based malware.

Heuristics 4

  • 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.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • 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
500f46eb522086ab7f6a049cfa3def487f5fc3772d95dd0fba2a4f8d8d78ae46
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 3366 bytes