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

Static analysis result for SHA-256 02444a47c0938b13…

MALICIOUS

Office (OLE) / .XLSX

41.5 KB Created: 2020-09-28 00:53:43 Authoring application: Microsoft Excel
MD5: 7e5f77e4e806e3685ff7600c6aa00d3a SHA-1: 4c4ed8f7897a96f7a8b636321a16d41d41a59148 SHA-256: 02444a47c0938b13bcff45b8d53060f1c3fb881c011886649d0ac58b89429977
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is flagged as a critical heuristic. This indicates the macro sheet is designed to automatically execute upon opening. The presence of dangerous formula APIs like RUN suggests the macro is intended to execute arbitrary code, likely downloading and running a second-stage payload. The specific functions and strings within the macro are heavily obfuscated, preventing a more detailed analysis of the payload's nature.

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
3628d3521c64c1ed48f12ab764392ca6227fc77e5bebb9a7d30a769a07dd7965		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 7968 bytes

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