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

Static analysis result for SHA-256 4e1c502ab9b2c68a…

MALICIOUS

Office (OLE) / .XLSX

35.5 KB Created: 2020-11-25 10:44:14 Authoring application: Microsoft Excel
MD5: 10177813f08e2116b2b8c96d1bd67aa8 SHA-1: 70a40ca6c3cd6b7ac4abcd7d2a302bdaf1d7e527 SHA-256: 4e1c502ab9b2c68ab10c86b7177175b139cad9cfe0fadd9c96f8f7f7269339e8
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The file contains Excel 4.0 macros, specifically an Auto_Open macro, which is a critical finding. The presence of dangerous formula APIs like RUN indicates that the macro is designed to execute arbitrary code. While the exact payload is not visible, the Auto_Open functionality strongly suggests a downloader or initial execution vector for further malicious activity.

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.
  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
b593eab6de95e809dd4fd5cbd5ff2c468bff37e02e26ca268fbf64d6c65998fb		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6517 bytes

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